leetcode-ac-tracking.md

# 🚀 LeetCode题解进度表

## LeetCode中文题大全

[leetcode中文题1-400](https://github.com/yanglr/leetcode-ac/tree/master/中文题1-2000/leetcode1-400)

[leetcode中文题401-2000](https://github.com/yanglr/leetcode-ac/tree/master/中文题1-2000/leetcode401-2000)



快速搜索题号、题解、代码、标签等，请善用 `Ctrl`+`F`（或者 `Command`+`F`）。


| 题号 | 题解 | 代码 | 标签 | 难度 | 有无锁 | AC状态 |
| --- | --- | --- | --- | --- | --- | --- |
| [0001](https://leetcode-cn.com/problems/two-sum) | 两数之和 |  | `数组`,`哈希表` | 简单 |  |  |
| [0002](https://leetcode-cn.com/problems/add-two-numbers) | 两数相加 |  | `递归`,`链表`,`数学` | 中等 |  |  |
| [0003](https://leetcode-cn.com/problems/longest-substring-without-repeating-characters) | 无重复字符的最长子串 |  | `哈希表`,`字符串`,`滑动窗口` | 中等 |  |  |
| [0004](https://leetcode-cn.com/problems/median-of-two-sorted-arrays) | 寻找两个正序数组的中位数 |  | `数组`,`二分查找`,`分治` | 困难 |  |  |
| [0005](https://leetcode-cn.com/problems/longest-palindromic-substring) | 最长回文子串 |  | `字符串`,`动态规划` | 中等 |  |  |
| [0006](https://leetcode-cn.com/problems/zigzag-conversion) | Z 字形变换 |  | `字符串` | 中等 |  |  |
| [0007](https://leetcode-cn.com/problems/reverse-integer) | 整数反转 |  | `数学` | 简单 |  |  |
| [0008](https://leetcode-cn.com/problems/string-to-integer-atoi) | 字符串转换整数 (atoi) |  | `字符串` | 中等 |  |  |
| [0009](https://leetcode-cn.com/problems/palindrome-number) | 回文数 |  | `数学` | 简单 |  | ✅ |
| [0010](https://leetcode-cn.com/problems/regular-expression-matching) | 正则表达式匹配 |  | `递归`,`字符串`,`动态规划` | 困难 |  |  |
| [0011](https://leetcode-cn.com/problems/container-with-most-water) | 盛最多水的容器 |  | `贪心`,`数组`,`双指针` | 中等 |  |  |
| [0012](https://leetcode-cn.com/problems/integer-to-roman) | 整数转罗马数字 |  | `哈希表`,`数学`,`字符串` | 中等 |  |  |
| [0013](https://leetcode-cn.com/problems/roman-to-integer) | 罗马数字转整数 |  | `哈希表`,`数学`,`字符串` | 简单 |  | ✅ |
| [0014](https://leetcode-cn.com/problems/longest-common-prefix) | 最长公共前缀 |  | `字符串` | 简单 |  |  |
| [0015](https://leetcode-cn.com/problems/3sum) | 三数之和 |  | `数组`,`双指针`,`排序` | 中等 |  |  |
| [0016](https://leetcode-cn.com/problems/3sum-closest) | 最接近的三数之和 |  | `数组`,`双指针`,`排序` | 中等 |  |  |
| [0017](https://leetcode-cn.com/problems/letter-combinations-of-a-phone-number) | 电话号码的字母组合 |  | `哈希表`,`字符串`,`回溯` | 中等 |  |  |
| [0018](https://leetcode-cn.com/problems/4sum) | 四数之和 |  | `数组`,`双指针`,`排序` | 中等 |  |  |
| [0019](https://leetcode-cn.com/problems/remove-nth-node-from-end-of-list) | 删除链表的倒数第 N 个结点 |  | `链表`,`双指针` | 中等 |  |  |
| [0020](https://leetcode-cn.com/problems/valid-parentheses) | 有效的括号 |  | `栈`,`字符串` | 简单 |  |  |
| [0021](https://leetcode-cn.com/problems/merge-two-sorted-lists) | 合并两个有序链表 |  | `递归`,`链表` | 简单 |  |  |
| [0022](https://leetcode-cn.com/problems/generate-parentheses) | 括号生成 |  | `字符串`,`动态规划`,`回溯` | 中等 |  |  |
| [0023](https://leetcode-cn.com/problems/merge-k-sorted-lists) | 合并K个升序链表 |  | `链表`,`分治`,`堆（优先队列）`,`归并排序` | 困难 |  |  |
| [0024](https://leetcode-cn.com/problems/swap-nodes-in-pairs) | 两两交换链表中的节点 |  | `递归`,`链表` | 中等 |  |  |
| [0025](https://leetcode-cn.com/problems/reverse-nodes-in-k-group) | K 个一组翻转链表 |  | `递归`,`链表` | 困难 |  |  |
| [0026](https://leetcode-cn.com/problems/remove-duplicates-from-sorted-array) | 删除有序数组中的重复项 |  | `数组`,`双指针` | 简单 |  |  |
| [0027](https://leetcode-cn.com/problems/remove-element) | 移除元素 |  | `数组`,`双指针` | 简单 |  |  |
| [0028](https://leetcode-cn.com/problems/implement-strstr) | 实现 strStr() |  | `双指针`,`字符串`,`字符串匹配` | 简单 |  |  |
| [0029](https://leetcode-cn.com/problems/divide-two-integers) | 两数相除 |  | `位运算`,`数学` | 中等 |  |  |
| [0030](https://leetcode-cn.com/problems/substring-with-concatenation-of-all-words) | 串联所有单词的子串 |  | `哈希表`,`字符串`,`滑动窗口` | 困难 |  |  |
| [0031](https://leetcode-cn.com/problems/next-permutation) | 下一个排列 |  | `数组`,`双指针` | 中等 |  |  |
| [0032](https://leetcode-cn.com/problems/longest-valid-parentheses) | 最长有效括号 |  | `栈`,`字符串`,`动态规划` | 困难 |  |  |
| [0033](https://leetcode-cn.com/problems/search-in-rotated-sorted-array) | 搜索旋转排序数组 |  | `数组`,`二分查找` | 中等 |  |  |
| [0034](https://leetcode-cn.com/problems/find-first-and-last-position-of-element-in-sorted-array) | 在排序数组中查找元素的第一个和最后一个位置 |  | `数组`,`二分查找` | 中等 |  |  |
| [0035](https://leetcode-cn.com/problems/search-insert-position) | 搜索插入位置 |  | `数组`,`二分查找` | 简单 |  |  |
| [0036](https://leetcode-cn.com/problems/valid-sudoku) | 有效的数独 |  | `数组`,`哈希表`,`矩阵` | 中等 |  |  |
| [0037](https://leetcode-cn.com/problems/sudoku-solver) | 解数独 |  | `数组`,`回溯`,`矩阵` | 困难 |  |  |
| [0038](https://leetcode-cn.com/problems/count-and-say) | 外观数列 |  | `字符串` | 中等 |  | ✅ |
| [0039](https://leetcode-cn.com/problems/combination-sum) | 组合总和 |  | `数组`,`回溯` | 中等 |  |  |
| [0040](https://leetcode-cn.com/problems/combination-sum-ii) | 组合总和 II |  | `数组`,`回溯` | 中等 |  |  |
| [0041](https://leetcode-cn.com/problems/first-missing-positive) | 缺失的第一个正数 |  | `数组`,`哈希表` | 困难 |  |  |
| [0042](https://leetcode-cn.com/problems/trapping-rain-water) | 接雨水 |  | `栈`,`数组`,`双指针`,`动态规划`,`单调栈` | 困难 |  |  |
| [0043](https://leetcode-cn.com/problems/multiply-strings) | 字符串相乘 |  | `数学`,`字符串`,`模拟` | 中等 |  |  |
| [0044](https://leetcode-cn.com/problems/wildcard-matching) | 通配符匹配 |  | `贪心`,`递归`,`字符串`,`动态规划` | 困难 |  |  |
| [0045](https://leetcode-cn.com/problems/jump-game-ii) | 跳跃游戏 II |  | `贪心`,`数组`,`动态规划` | 中等 |  |  |
| [0046](https://leetcode-cn.com/problems/permutations) | 全排列 |  | `数组`,`回溯` | 中等 |  |  |
| [0047](https://leetcode-cn.com/problems/permutations-ii) | 全排列 II |  | `数组`,`回溯` | 中等 |  |  |
| [0048](https://leetcode-cn.com/problems/rotate-image) | 旋转图像 |  | `数组`,`数学`,`矩阵` | 中等 |  |  |
| [0049](https://leetcode-cn.com/problems/group-anagrams) | 字母异位词分组 |  | `哈希表`,`字符串`,`排序` | 中等 |  |  |
| [0050](https://leetcode-cn.com/problems/powx-n) | Pow(x, n) |  | `递归`,`数学` | 中等 |  |  |
| [0051](https://leetcode-cn.com/problems/n-queens) | N 皇后 |  | `数组`,`回溯` | 困难 |  |  |
| [0052](https://leetcode-cn.com/problems/n-queens-ii) | N皇后 II |  | `回溯` | 困难 |  |  |
| [0053](https://leetcode-cn.com/problems/maximum-subarray) | 最大子序和 |  | `数组`,`分治`,`动态规划` | 简单 |  |  |
| [0054](https://leetcode-cn.com/problems/spiral-matrix) | 螺旋矩阵 |  | `数组`,`矩阵`,`模拟` | 中等 |  |  |
| [0055](https://leetcode-cn.com/problems/jump-game) | 跳跃游戏 |  | `贪心`,`数组`,`动态规划` | 中等 |  |  |
| [0056](https://leetcode-cn.com/problems/merge-intervals) | 合并区间 |  | `数组`,`排序` | 中等 |  |  |
| [0057](https://leetcode-cn.com/problems/insert-interval) | 插入区间 |  | `数组` | 中等 |  |  |
| [0058](https://leetcode-cn.com/problems/length-of-last-word) | 最后一个单词的长度 |  | `字符串` | 简单 |  | ✅ |
| [0059](https://leetcode-cn.com/problems/spiral-matrix-ii) | 螺旋矩阵 II |  | `数组`,`矩阵`,`模拟` | 中等 |  |  |
| [0060](https://leetcode-cn.com/problems/permutation-sequence) | 排列序列 |  | `递归`,`数学` | 困难 |  |  |
| [0061](https://leetcode-cn.com/problems/rotate-list) | 旋转链表 |  | `链表`,`双指针` | 中等 |  |  |
| [0062](https://leetcode-cn.com/problems/unique-paths) | 不同路径 |  | `数学`,`动态规划`,`组合数学` | 中等 |  |  |
| [0063](https://leetcode-cn.com/problems/unique-paths-ii) | 不同路径 II |  | `数组`,`动态规划`,`矩阵` | 中等 |  |  |
| [0064](https://leetcode-cn.com/problems/minimum-path-sum) | 最小路径和 |  | `数组`,`动态规划`,`矩阵` | 中等 |  |  |
| [0065](https://leetcode-cn.com/problems/valid-number) | 有效数字 |  | `字符串` | 困难 |  |  |
| [0066](https://leetcode-cn.com/problems/plus-one) | 加一 |  | `数组`,`数学` | 简单 |  |  |
| [0067](https://leetcode-cn.com/problems/add-binary) | 二进制求和 |  | `位运算`,`数学`,`字符串`,`模拟` | 简单 |  | ✅ |
| [0068](https://leetcode-cn.com/problems/text-justification) | 文本左右对齐 |  | `字符串`,`模拟` | 困难 |  |  |
| [0069](https://leetcode-cn.com/problems/sqrtx) | x 的平方根 |  | `数学`,`二分查找` | 简单 |  |  |
| [0070](https://leetcode-cn.com/problems/climbing-stairs) | 爬楼梯 |  | `记忆化搜索`,`数学`,`动态规划` | 简单 |  |  |
| [0071](https://leetcode-cn.com/problems/simplify-path) | 简化路径 |  | `栈`,`字符串` | 中等 |  |  |
| [0072](https://leetcode-cn.com/problems/edit-distance) | 编辑距离 |  | `字符串`,`动态规划` | 困难 |  |  |
| [0073](https://leetcode-cn.com/problems/set-matrix-zeroes) | 矩阵置零 |  | `数组`,`哈希表`,`矩阵` | 中等 |  |  |
| [0074](https://leetcode-cn.com/problems/search-a-2d-matrix) | 搜索二维矩阵 |  | `数组`,`二分查找`,`矩阵` | 中等 |  |  |
| [0075](https://leetcode-cn.com/problems/sort-colors) | 颜色分类 |  | `数组`,`双指针`,`排序` | 中等 |  |  |
| [0076](https://leetcode-cn.com/problems/minimum-window-substring) | 最小覆盖子串 |  | `哈希表`,`字符串`,`滑动窗口` | 困难 |  |  |
| [0077](https://leetcode-cn.com/problems/combinations) | 组合 |  | `数组`,`回溯` | 中等 |  |  |
| [0078](https://leetcode-cn.com/problems/subsets) | 子集 |  | `位运算`,`数组`,`回溯` | 中等 |  |  |
| [0079](https://leetcode-cn.com/problems/word-search) | 单词搜索 |  | `数组`,`回溯`,`矩阵` | 中等 |  |  |
| [0080](https://leetcode-cn.com/problems/remove-duplicates-from-sorted-array-ii) | 删除有序数组中的重复项 II |  | `数组`,`双指针` | 中等 |  |  |
| [0081](https://leetcode-cn.com/problems/search-in-rotated-sorted-array-ii) | 搜索旋转排序数组 II |  | `数组`,`二分查找` | 中等 |  |  |
| [0082](https://leetcode-cn.com/problems/remove-duplicates-from-sorted-list-ii) | 删除排序链表中的重复元素 II |  | `链表`,`双指针` | 中等 |  |  |
| [0083](https://leetcode-cn.com/problems/remove-duplicates-from-sorted-list) | 删除排序链表中的重复元素 |  | `链表` | 简单 |  |  |
| [0084](https://leetcode-cn.com/problems/largest-rectangle-in-histogram) | 柱状图中最大的矩形 |  | `栈`,`数组`,`单调栈` | 困难 |  |  |
| [0085](https://leetcode-cn.com/problems/maximal-rectangle) | 最大矩形 |  | `栈`,`数组`,`动态规划`,`矩阵`,`单调栈` | 困难 |  |  |
| [0086](https://leetcode-cn.com/problems/partition-list) | 分隔链表 |  | `链表`,`双指针` | 中等 |  |  |
| [0087](https://leetcode-cn.com/problems/scramble-string) | 扰乱字符串 |  | `字符串`,`动态规划` | 困难 |  |  |
| [0088](https://leetcode-cn.com/problems/merge-sorted-array) | 合并两个有序数组 |  | `数组`,`双指针`,`排序` | 简单 |  |  |
| [0089](https://leetcode-cn.com/problems/gray-code) | 格雷编码 |  | `位运算`,`数学`,`回溯` | 中等 |  | ✅ |
| [0090](https://leetcode-cn.com/problems/subsets-ii) | 子集 II |  | `位运算`,`数组`,`回溯` | 中等 |  |  |
| [0091](https://leetcode-cn.com/problems/decode-ways) | 解码方法 |  | `字符串`,`动态规划` | 中等 |  |  |
| [0092](https://leetcode-cn.com/problems/reverse-linked-list-ii) | 反转链表 II |  | `链表` | 中等 |  |  |
| [0093](https://leetcode-cn.com/problems/restore-ip-addresses) | 复原 IP 地址 |  | `字符串`,`回溯` | 中等 |  |  |
| [0094](https://leetcode-cn.com/problems/binary-tree-inorder-traversal) | 二叉树的中序遍历 |  | `栈`,`树`,`深度优先搜索`,`二叉树` | 简单 |  |  |
| [0095](https://leetcode-cn.com/problems/unique-binary-search-trees-ii) | 不同的二叉搜索树 II |  | `树`,`二叉搜索树`,`动态规划`,`回溯`,`二叉树` | 中等 |  |  |
| [0096](https://leetcode-cn.com/problems/unique-binary-search-trees) | 不同的二叉搜索树 |  | `树`,`二叉搜索树`,`数学`,`动态规划`,`二叉树` | 中等 |  |  |
| [0097](https://leetcode-cn.com/problems/interleaving-string) | 交错字符串 |  | `字符串`,`动态规划` | 中等 |  |  |
| [0098](https://leetcode-cn.com/problems/validate-binary-search-tree) | 验证二叉搜索树 |  | `树`,`深度优先搜索`,`二叉搜索树`,`二叉树` | 中等 |  |  |
| [0099](https://leetcode-cn.com/problems/recover-binary-search-tree) | 恢复二叉搜索树 |  | `树`,`深度优先搜索`,`二叉搜索树`,`二叉树` | 中等 |  |  |
| [0100](https://leetcode-cn.com/problems/same-tree) | 相同的树 |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉树` | 简单 |  |  |
| [0101](https://leetcode-cn.com/problems/symmetric-tree) | 对称二叉树 |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉树` | 简单 |  |  |
| [0102](https://leetcode-cn.com/problems/binary-tree-level-order-traversal) | 二叉树的层序遍历 |  | `树`,`广度优先搜索`,`二叉树` | 中等 |  |  |
| [0103](https://leetcode-cn.com/problems/binary-tree-zigzag-level-order-traversal) | 二叉树的锯齿形层序遍历 |  | `树`,`广度优先搜索`,`二叉树` | 中等 |  |  |
| [0104](https://leetcode-cn.com/problems/maximum-depth-of-binary-tree) | 二叉树的最大深度 |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉树` | 简单 |  |  |
| [0105](https://leetcode-cn.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal) | 从前序与中序遍历序列构造二叉树 |  | `树`,`数组`,`哈希表`,`分治`,`二叉树` | 中等 |  |  |
| [0106](https://leetcode-cn.com/problems/construct-binary-tree-from-inorder-and-postorder-traversal) | 从中序与后序遍历序列构造二叉树 |  | `树`,`数组`,`哈希表`,`分治`,`二叉树` | 中等 |  |  |
| [0107](https://leetcode-cn.com/problems/binary-tree-level-order-traversal-ii) | 二叉树的层序遍历 II |  | `树`,`广度优先搜索`,`二叉树` | 中等 |  |  |
| [0108](https://leetcode-cn.com/problems/convert-sorted-array-to-binary-search-tree) | 将有序数组转换为二叉搜索树 |  | `树`,`二叉搜索树`,`数组`,`分治`,`二叉树` | 简单 |  |  |
| [0109](https://leetcode-cn.com/problems/convert-sorted-list-to-binary-search-tree) | 有序链表转换二叉搜索树 |  | `树`,`二叉搜索树`,`链表`,`分治`,`二叉树` | 中等 |  |  |
| [0110](https://leetcode-cn.com/problems/balanced-binary-tree) | 平衡二叉树 |  | `树`,`深度优先搜索`,`二叉树` | 简单 |  |  |
| [0111](https://leetcode-cn.com/problems/minimum-depth-of-binary-tree) | 二叉树的最小深度 |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉树` | 简单 |  |  |
| [0112](https://leetcode-cn.com/problems/path-sum) | 路径总和 |  | `树`,`深度优先搜索`,`二叉树` | 简单 |  |  |
| [0113](https://leetcode-cn.com/problems/path-sum-ii) | 路径总和 II |  | `树`,`深度优先搜索`,`回溯`,`二叉树` | 中等 |  |  |
| [0114](https://leetcode-cn.com/problems/flatten-binary-tree-to-linked-list) | 二叉树展开为链表 |  | `栈`,`树`,`深度优先搜索`,`链表`,`二叉树` | 中等 |  |  |
| [0115](https://leetcode-cn.com/problems/distinct-subsequences) | 不同的子序列 |  | `字符串`,`动态规划` | 困难 |  |  |
| [0116](https://leetcode-cn.com/problems/populating-next-right-pointers-in-each-node) | 填充每个节点的下一个右侧节点指针 |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉树` | 中等 |  |  |
| [0117](https://leetcode-cn.com/problems/populating-next-right-pointers-in-each-node-ii) | 填充每个节点的下一个右侧节点指针 II |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉树` | 中等 |  |  |
| [0118](https://leetcode-cn.com/problems/pascals-triangle) | 杨辉三角 |  | `数组`,`动态规划` | 简单 |  |  |
| [0119](https://leetcode-cn.com/problems/pascals-triangle-ii) | 杨辉三角 II |  | `数组`,`动态规划` | 简单 |  |  |
| [0120](https://leetcode-cn.com/problems/triangle) | 三角形最小路径和 |  | `数组`,`动态规划` | 中等 |  |  |
| [0121](https://leetcode-cn.com/problems/best-time-to-buy-and-sell-stock) | 买卖股票的最佳时机 |  | `数组`,`动态规划` | 简单 |  |  |
| [0122](https://leetcode-cn.com/problems/best-time-to-buy-and-sell-stock-ii) | 买卖股票的最佳时机 II |  | `贪心`,`数组`,`动态规划` | 简单 |  |  |
| [0123](https://leetcode-cn.com/problems/best-time-to-buy-and-sell-stock-iii) | 买卖股票的最佳时机 III |  | `数组`,`动态规划` | 困难 |  |  |
| [0124](https://leetcode-cn.com/problems/binary-tree-maximum-path-sum) | 二叉树中的最大路径和 |  | `树`,`深度优先搜索`,`动态规划`,`二叉树` | 困难 |  |  |
| [0125](https://leetcode-cn.com/problems/valid-palindrome) | 验证回文串 |  | `双指针`,`字符串` | 简单 |  |  |
| [0126](https://leetcode-cn.com/problems/word-ladder-ii) | 单词接龙 II |  | `广度优先搜索`,`哈希表`,`字符串`,`回溯` | 困难 |  |  |
| [0127](https://leetcode-cn.com/problems/word-ladder) | 单词接龙 |  | `广度优先搜索`,`哈希表`,`字符串` | 困难 |  |  |
| [0128](https://leetcode-cn.com/problems/longest-consecutive-sequence) | 最长连续序列 |  | `并查集`,`数组`,`哈希表` | 中等 |  |  |
| [0129](https://leetcode-cn.com/problems/sum-root-to-leaf-numbers) | 求根节点到叶节点数字之和 |  | `树`,`深度优先搜索`,`二叉树` | 中等 |  |  |
| [0130](https://leetcode-cn.com/problems/surrounded-regions) | 被围绕的区域 |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`数组`,`矩阵` | 中等 |  |  |
| [0131](https://leetcode-cn.com/problems/palindrome-partitioning) | 分割回文串 |  | `字符串`,`动态规划`,`回溯` | 中等 |  |  |
| [0132](https://leetcode-cn.com/problems/palindrome-partitioning-ii) | 分割回文串 II |  | `字符串`,`动态规划` | 困难 |  |  |
| [0133](https://leetcode-cn.com/problems/clone-graph) | 克隆图 |  | `深度优先搜索`,`广度优先搜索`,`图`,`哈希表` | 中等 |  |  |
| [0134](https://leetcode-cn.com/problems/gas-station) | 加油站 |  | `贪心`,`数组` | 中等 |  |  |
| [0135](https://leetcode-cn.com/problems/candy) | 分发糖果 |  | `贪心`,`数组` | 困难 |  |  |
| [0136](https://leetcode-cn.com/problems/single-number) | 只出现一次的数字 |  | `位运算`,`数组` | 简单 |  | ✅ |
| [0137](https://leetcode-cn.com/problems/single-number-ii) | 只出现一次的数字 II |  | `位运算`,`数组` | 中等 |  |  |
| [0138](https://leetcode-cn.com/problems/copy-list-with-random-pointer) | 复制带随机指针的链表 |  | `哈希表`,`链表` | 中等 |  |  |
| [0139](https://leetcode-cn.com/problems/word-break) | 单词拆分 |  | `字典树`,`记忆化搜索`,`哈希表`,`字符串`,`动态规划` | 中等 |  |  |
| [0140](https://leetcode-cn.com/problems/word-break-ii) | 单词拆分 II |  | `字典树`,`记忆化搜索`,`哈希表`,`字符串`,`动态规划`,`回溯` | 困难 |  |  |
| [0141](https://leetcode-cn.com/problems/linked-list-cycle) | 环形链表 |  | `哈希表`,`链表`,`双指针` | 简单 |  |  |
| [0142](https://leetcode-cn.com/problems/linked-list-cycle-ii) | 环形链表 II |  | `哈希表`,`链表`,`双指针` | 中等 |  |  |
| [0143](https://leetcode-cn.com/problems/reorder-list) | 重排链表 |  | `栈`,`递归`,`链表`,`双指针` | 中等 |  |  |
| [0144](https://leetcode-cn.com/problems/binary-tree-preorder-traversal) | 二叉树的前序遍历 |  | `栈`,`树`,`深度优先搜索`,`二叉树` | 简单 |  |  |
| [0145](https://leetcode-cn.com/problems/binary-tree-postorder-traversal) | 二叉树的后序遍历 |  | `栈`,`树`,`深度优先搜索`,`二叉树` | 简单 |  |  |
| [0146](https://leetcode-cn.com/problems/lru-cache) | LRU 缓存机制 |  | `设计`,`哈希表`,`链表`,`双向链表` | 中等 |  |  |
| [0147](https://leetcode-cn.com/problems/insertion-sort-list) | 对链表进行插入排序 |  | `链表`,`排序` | 中等 |  |  |
| [0148](https://leetcode-cn.com/problems/sort-list) | 排序链表 |  | `链表`,`双指针`,`分治`,`排序`,`归并排序` | 中等 |  |  |
| [0149](https://leetcode-cn.com/problems/max-points-on-a-line) | 直线上最多的点数 |  | `几何`,`哈希表`,`数学` | 困难 |  |  |
| [0150](https://leetcode-cn.com/problems/evaluate-reverse-polish-notation) | 逆波兰表达式求值 |  | `栈`,`数组`,`数学` | 中等 |  |  |
| [0151](https://leetcode-cn.com/problems/reverse-words-in-a-string) | 翻转字符串里的单词 |  | `双指针`,`字符串` | 中等 |  |  |
| [0152](https://leetcode-cn.com/problems/maximum-product-subarray) | 乘积最大子数组 |  | `数组`,`动态规划` | 中等 |  |  |
| [0153](https://leetcode-cn.com/problems/find-minimum-in-rotated-sorted-array) | 寻找旋转排序数组中的最小值 |  | `数组`,`二分查找` | 中等 |  |  |
| [0154](https://leetcode-cn.com/problems/find-minimum-in-rotated-sorted-array-ii) | 寻找旋转排序数组中的最小值 II |  | `数组`,`二分查找` | 困难 |  |  |
| [0155](https://leetcode-cn.com/problems/min-stack) | 最小栈 |  | `栈`,`设计` | 简单 |  |  |
| [0156](https://leetcode-cn.com/problems/binary-tree-upside-down) | 上下翻转二叉树 |  | `树`,`深度优先搜索`,`二叉树` | 中等 | 🔒 |  |
| [0157](https://leetcode-cn.com/problems/read-n-characters-given-read4) | 用 Read4 读取 N 个字符 |  | `字符串`,`交互`,`模拟` | 简单 | 🔒 |  |
| [0158](https://leetcode-cn.com/problems/read-n-characters-given-read4-ii-call-multiple-times) | 用 Read4 读取 N 个字符 II |  | `字符串`,`交互`,`模拟` | 困难 | 🔒 |  |
| [0159](https://leetcode-cn.com/problems/longest-substring-with-at-most-two-distinct-characters) | 至多包含两个不同字符的最长子串 |  | `哈希表`,`字符串`,`滑动窗口` | 中等 | 🔒 |  |
| [0160](https://leetcode-cn.com/problems/intersection-of-two-linked-lists) | 相交链表 |  | `哈希表`,`链表`,`双指针` | 简单 |  |  |
| [0161](https://leetcode-cn.com/problems/one-edit-distance) | 相隔为 1 的编辑距离 |  | `双指针`,`字符串` | 中等 | 🔒 |  |
| [0162](https://leetcode-cn.com/problems/find-peak-element) | 寻找峰值 |  | `数组`,`二分查找` | 中等 |  |  |
| [0163](https://leetcode-cn.com/problems/missing-ranges) | 缺失的区间 |  | `数组` | 简单 | 🔒 |  |
| [0164](https://leetcode-cn.com/problems/maximum-gap) | 最大间距 |  | `数组`,`桶排序`,`基数排序`,`排序` | 困难 |  |  |
| [0165](https://leetcode-cn.com/problems/compare-version-numbers) | 比较版本号 |  | `双指针`,`字符串` | 中等 |  |  |
| [0166](https://leetcode-cn.com/problems/fraction-to-recurring-decimal) | 分数到小数 |  | `哈希表`,`数学`,`字符串` | 中等 |  |  |
| [0167](https://leetcode-cn.com/problems/two-sum-ii-input-array-is-sorted) | 两数之和 II - 输入有序数组 |  | `数组`,`双指针`,`二分查找` | 简单 |  |  |
| [0168](https://leetcode-cn.com/problems/excel-sheet-column-title) | Excel表列名称 |  | `数学`,`字符串` | 简单 |  |  |
| [0169](https://leetcode-cn.com/problems/majority-element) | 多数元素 |  | `数组`,`哈希表`,`分治`,`计数`,`排序` | 简单 |  |  |
| [0170](https://leetcode-cn.com/problems/two-sum-iii-data-structure-design) | 两数之和 III - 数据结构设计 |  | `设计`,`数组`,`哈希表`,`双指针`,`数据流` | 简单 | 🔒 |  |
| [0171](https://leetcode-cn.com/problems/excel-sheet-column-number) | Excel表列序号 |  | `数学`,`字符串` | 简单 |  |  |
| [0172](https://leetcode-cn.com/problems/factorial-trailing-zeroes) | 阶乘后的零 |  | `数学` | 简单 |  |  |
| [0173](https://leetcode-cn.com/problems/binary-search-tree-iterator) | 二叉搜索树迭代器 |  | `栈`,`树`,`设计`,`二叉搜索树`,`二叉树`,`迭代器` | 中等 |  |  |
| [0174](https://leetcode-cn.com/problems/dungeon-game) | 地下城游戏 |  | `数组`,`动态规划`,`矩阵` | 困难 |  |  |
| [0175](https://leetcode-cn.com/problems/combine-two-tables) | 组合两个表 |  | `数据库` | 简单 |  |  |
| [0176](https://leetcode-cn.com/problems/second-highest-salary) | 第二高的薪水 |  | `数据库` | 简单 |  |  |
| [0177](https://leetcode-cn.com/problems/nth-highest-salary) | 第N高的薪水 |  | `数据库` | 中等 |  |  |
| [0178](https://leetcode-cn.com/problems/rank-scores) | 分数排名 |  | `数据库` | 中等 |  |  |
| [0179](https://leetcode-cn.com/problems/largest-number) | 最大数 |  | `贪心`,`字符串`,`排序` | 中等 |  |  |
| [0180](https://leetcode-cn.com/problems/consecutive-numbers) | 连续出现的数字 |  | `数据库` | 中等 |  |  |
| [0181](https://leetcode-cn.com/problems/employees-earning-more-than-their-managers) | 超过经理收入的员工 |  | `数据库` | 简单 |  |  |
| [0182](https://leetcode-cn.com/problems/duplicate-emails) | 查找重复的电子邮箱 |  | `数据库` | 简单 |  |  |
| [0183](https://leetcode-cn.com/problems/customers-who-never-order) | 从不订购的客户 |  | `数据库` | 简单 |  |  |
| [0184](https://leetcode-cn.com/problems/department-highest-salary) | 部门工资最高的员工 |  | `数据库` | 中等 |  |  |
| [0185](https://leetcode-cn.com/problems/department-top-three-salaries) | 部门工资前三高的所有员工 |  | `数据库` | 困难 |  |  |
| [0186](https://leetcode-cn.com/problems/reverse-words-in-a-string-ii) | 翻转字符串里的单词 II |  | `双指针`,`字符串` | 中等 | 🔒 |  |
| [0187](https://leetcode-cn.com/problems/repeated-dna-sequences) | 重复的DNA序列 |  | `位运算`,`哈希表`,`字符串`,`滑动窗口`,`哈希函数`,`滚动哈希` | 中等 |  |  |
| [0188](https://leetcode-cn.com/problems/best-time-to-buy-and-sell-stock-iv) | 买卖股票的最佳时机 IV |  | `数组`,`动态规划` | 困难 |  |  |
| [0189](https://leetcode-cn.com/problems/rotate-array) | 旋转数组 |  | `数组`,`数学`,`双指针` | 中等 |  |  |
| [0190](https://leetcode-cn.com/problems/reverse-bits) | 颠倒二进制位 |  | `位运算`,`分治` | 简单 |  |  |
| [0191](https://leetcode-cn.com/problems/number-of-1-bits) | 位1的个数 |  | `位运算` | 简单 |  | ✅ |
| [0192](https://leetcode-cn.com/problems/word-frequency) | 统计词频 |  |  | 中等 |  |  |
| [0193](https://leetcode-cn.com/problems/valid-phone-numbers) | 有效电话号码 |  |  | 简单 |  |  |
| [0194](https://leetcode-cn.com/problems/transpose-file) | 转置文件 |  |  | 中等 |  |  |
| [0195](https://leetcode-cn.com/problems/tenth-line) | 第十行 |  |  | 简单 |  |  |
| [0196](https://leetcode-cn.com/problems/delete-duplicate-emails) | 删除重复的电子邮箱 |  | `数据库` | 简单 |  |  |
| [0197](https://leetcode-cn.com/problems/rising-temperature) | 上升的温度 |  | `数据库` | 简单 |  |  |
| [0198](https://leetcode-cn.com/problems/house-robber) | 打家劫舍 |  | `数组`,`动态规划` | 中等 |  |  |
| [0199](https://leetcode-cn.com/problems/binary-tree-right-side-view) | 二叉树的右视图 |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉树` | 中等 |  |  |
| [0200](https://leetcode-cn.com/problems/number-of-islands) | 岛屿数量 |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`数组`,`矩阵` | 中等 |  |  |
| [0201](https://leetcode-cn.com/problems/bitwise-and-of-numbers-range) | 数字范围按位与 |  | `位运算` | 中等 |  |  |
| [0202](https://leetcode-cn.com/problems/happy-number) | 快乐数 |  | `哈希表`,`数学`,`双指针` | 简单 |  | ✅ |
| [0203](https://leetcode-cn.com/problems/remove-linked-list-elements) | 移除链表元素 |  | `递归`,`链表` | 简单 |  |  |
| [0204](https://leetcode-cn.com/problems/count-primes) | 计数质数 |  | `数组`,`数学`,`枚举`,`数论` | 简单 |  | ✅ |
| [0205](https://leetcode-cn.com/problems/isomorphic-strings) | 同构字符串 |  | `哈希表`,`字符串` | 简单 |  |  |
| [0206](https://leetcode-cn.com/problems/reverse-linked-list) | 反转链表 |  | `递归`,`链表` | 简单 |  |  |
| [0207](https://leetcode-cn.com/problems/course-schedule) | 课程表 |  | `深度优先搜索`,`广度优先搜索`,`图`,`拓扑排序` | 中等 |  |  |
| [0208](https://leetcode-cn.com/problems/implement-trie-prefix-tree) | 实现 Trie (前缀树) |  | `设计`,`字典树`,`哈希表`,`字符串` | 中等 |  |  |
| [0209](https://leetcode-cn.com/problems/minimum-size-subarray-sum) | 长度最小的子数组 |  | `数组`,`二分查找`,`前缀和`,`滑动窗口` | 中等 |  |  |
| [0210](https://leetcode-cn.com/problems/course-schedule-ii) | 课程表 II |  | `深度优先搜索`,`广度优先搜索`,`图`,`拓扑排序` | 中等 |  |  |
| [0211](https://leetcode-cn.com/problems/design-add-and-search-words-data-structure) | 添加与搜索单词 - 数据结构设计 |  | `深度优先搜索`,`设计`,`字典树`,`字符串` | 中等 |  |  |
| [0212](https://leetcode-cn.com/problems/word-search-ii) | 单词搜索 II |  | `字典树`,`数组`,`字符串`,`回溯`,`矩阵` | 困难 |  |  |
| [0213](https://leetcode-cn.com/problems/house-robber-ii) | 打家劫舍 II |  | `数组`,`动态规划` | 中等 |  |  |
| [0214](https://leetcode-cn.com/problems/shortest-palindrome) | 最短回文串 |  | `字符串`,`字符串匹配`,`哈希函数`,`滚动哈希` | 困难 |  |  |
| [0215](https://leetcode-cn.com/problems/kth-largest-element-in-an-array) | 数组中的第K个最大元素 |  | `数组`,`分治`,`快速选择`,`排序`,`堆（优先队列）` | 中等 |  |  |
| [0216](https://leetcode-cn.com/problems/combination-sum-iii) | 组合总和 III |  | `数组`,`回溯` | 中等 |  |  |
| [0217](https://leetcode-cn.com/problems/contains-duplicate) | 存在重复元素 |  | `数组`,`哈希表`,`排序` | 简单 |  |  |
| [0218](https://leetcode-cn.com/problems/the-skyline-problem) | 天际线问题 |  | `树状数组`,`线段树`,`数组`,`分治`,`有序集合`,`扫描线`,`堆（优先队列）` | 困难 |  |  |
| [0219](https://leetcode-cn.com/problems/contains-duplicate-ii) | 存在重复元素 II |  | `数组`,`哈希表`,`滑动窗口` | 简单 |  |  |
| [0220](https://leetcode-cn.com/problems/contains-duplicate-iii) | 存在重复元素 III |  | `数组`,`桶排序`,`有序集合`,`排序`,`滑动窗口` | 中等 |  |  |
| [0221](https://leetcode-cn.com/problems/maximal-square) | 最大正方形 |  | `数组`,`动态规划`,`矩阵` | 中等 |  |  |
| [0222](https://leetcode-cn.com/problems/count-complete-tree-nodes) | 完全二叉树的节点个数 |  | `树`,`深度优先搜索`,`二分查找`,`二叉树` | 中等 |  |  |
| [0223](https://leetcode-cn.com/problems/rectangle-area) | 矩形面积 |  | `几何`,`数学` | 中等 |  |  |
| [0224](https://leetcode-cn.com/problems/basic-calculator) | 基本计算器 |  | `栈`,`递归`,`数学`,`字符串` | 困难 |  |  |
| [0225](https://leetcode-cn.com/problems/implement-stack-using-queues) | 用队列实现栈 |  | `栈`,`设计`,`队列` | 简单 |  |  |
| [0226](https://leetcode-cn.com/problems/invert-binary-tree) | 翻转二叉树 |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉树` | 简单 |  |  |
| [0227](https://leetcode-cn.com/problems/basic-calculator-ii) | 基本计算器 II |  | `栈`,`数学`,`字符串` | 中等 |  |  |
| [0228](https://leetcode-cn.com/problems/summary-ranges) | 汇总区间 |  | `数组` | 简单 |  |  |
| [0229](https://leetcode-cn.com/problems/majority-element-ii) | 求众数 II |  | `数组`,`哈希表`,`计数`,`排序` | 中等 |  |  |
| [0230](https://leetcode-cn.com/problems/kth-smallest-element-in-a-bst) | 二叉搜索树中第K小的元素 |  | `树`,`深度优先搜索`,`二叉搜索树`,`二叉树` | 中等 |  |  |
| [0231](https://leetcode-cn.com/problems/power-of-two) | 2 的幂 |  | `位运算`,`递归`,`数学` | 简单 |  |  |
| [0232](https://leetcode-cn.com/problems/implement-queue-using-stacks) | 用栈实现队列 |  | `栈`,`设计`,`队列` | 简单 |  |  |
| [0233](https://leetcode-cn.com/problems/number-of-digit-one) | 数字 1 的个数 |  | `递归`,`数学`,`动态规划` | 困难 |  |  |
| [0234](https://leetcode-cn.com/problems/palindrome-linked-list) | 回文链表 |  | `栈`,`递归`,`链表`,`双指针` | 简单 |  |  |
| [0235](https://leetcode-cn.com/problems/lowest-common-ancestor-of-a-binary-search-tree) | 二叉搜索树的最近公共祖先 |  | `树`,`深度优先搜索`,`二叉搜索树`,`二叉树` | 简单 |  |  |
| [0236](https://leetcode-cn.com/problems/lowest-common-ancestor-of-a-binary-tree) | 二叉树的最近公共祖先 |  | `树`,`深度优先搜索`,`二叉树` | 中等 |  |  |
| [0237](https://leetcode-cn.com/problems/delete-node-in-a-linked-list) | 删除链表中的节点 |  | `链表` | 简单 |  |  |
| [0238](https://leetcode-cn.com/problems/product-of-array-except-self) | 除自身以外数组的乘积 |  | `数组`,`前缀和` | 中等 |  |  |
| [0239](https://leetcode-cn.com/problems/sliding-window-maximum) | 滑动窗口最大值 |  | `队列`,`数组`,`滑动窗口`,`单调队列`,`堆（优先队列）` | 困难 |  |  |
| [0240](https://leetcode-cn.com/problems/search-a-2d-matrix-ii) | 搜索二维矩阵 II |  | `数组`,`二分查找`,`分治`,`矩阵` | 中等 |  |  |
| [0241](https://leetcode-cn.com/problems/different-ways-to-add-parentheses) | 为运算表达式设计优先级 |  | `递归`,`记忆化搜索`,`数学`,`字符串`,`动态规划` | 中等 |  |  |
| [0242](https://leetcode-cn.com/problems/valid-anagram) | 有效的字母异位词 |  | `哈希表`,`字符串`,`排序` | 简单 |  |  |
| [0243](https://leetcode-cn.com/problems/shortest-word-distance) | 最短单词距离 |  | `数组`,`字符串` | 简单 | 🔒 |  |
| [0244](https://leetcode-cn.com/problems/shortest-word-distance-ii) | 最短单词距离 II |  | `设计`,`数组`,`哈希表`,`双指针`,`字符串` | 中等 | 🔒 |  |
| [0245](https://leetcode-cn.com/problems/shortest-word-distance-iii) | 最短单词距离 III |  | `数组`,`字符串` | 中等 | 🔒 |  |
| [0246](https://leetcode-cn.com/problems/strobogrammatic-number) | 中心对称数 |  | `哈希表`,`双指针`,`字符串` | 简单 | 🔒 |  |
| [0247](https://leetcode-cn.com/problems/strobogrammatic-number-ii) | 中心对称数 II |  | `递归`,`数组`,`字符串` | 中等 | 🔒 |  |
| [0248](https://leetcode-cn.com/problems/strobogrammatic-number-iii) | 中心对称数 III |  | `递归`,`数组`,`字符串` | 困难 | 🔒 |  |
| [0249](https://leetcode-cn.com/problems/group-shifted-strings) | 移位字符串分组 |  | `数组`,`哈希表`,`字符串` | 中等 | 🔒 |  |
| [0250](https://leetcode-cn.com/problems/count-univalue-subtrees) | 统计同值子树 |  | `树`,`深度优先搜索`,`二叉树` | 中等 | 🔒 |  |
| [0251](https://leetcode-cn.com/problems/flatten-2d-vector) | 展开二维向量 |  | `设计`,`数组`,`双指针`,`迭代器` | 中等 | 🔒 |  |
| [0252](https://leetcode-cn.com/problems/meeting-rooms) | 会议室 |  | `数组`,`排序` | 简单 | 🔒 |  |
| [0253](https://leetcode-cn.com/problems/meeting-rooms-ii) | 会议室 II |  | `贪心`,`数组`,`双指针`,`排序`,`堆（优先队列）` | 中等 | 🔒 |  |
| [0254](https://leetcode-cn.com/problems/factor-combinations) | 因子的组合 |  | `数组`,`回溯` | 中等 | 🔒 |  |
| [0255](https://leetcode-cn.com/problems/verify-preorder-sequence-in-binary-search-tree) | 验证前序遍历序列二叉搜索树 |  | `栈`,`树`,`二叉搜索树`,`递归`,`二叉树`,`单调栈` | 中等 | 🔒 |  |
| [0256](https://leetcode-cn.com/problems/paint-house) | 粉刷房子 |  | `数组`,`动态规划` | 中等 | 🔒 |  |
| [0257](https://leetcode-cn.com/problems/binary-tree-paths) | 二叉树的所有路径 |  | `树`,`深度优先搜索`,`字符串`,`二叉树` | 简单 |  |  |
| [0258](https://leetcode-cn.com/problems/add-digits) | 各位相加 |  | `数学`,`数论`,`模拟` | 简单 |  |  |
| [0259](https://leetcode-cn.com/problems/3sum-smaller) | 较小的三数之和 |  | `数组`,`双指针`,`二分查找`,`排序` | 中等 | 🔒 |  |
| [0260](https://leetcode-cn.com/problems/single-number-iii) | 只出现一次的数字 III |  | `位运算`,`数组` | 中等 |  |  |
| [0261](https://leetcode-cn.com/problems/graph-valid-tree) | 以图判树 |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`图` | 中等 | 🔒 |  |
| [0262](https://leetcode-cn.com/problems/trips-and-users) | 行程和用户 |  | `数据库` | 困难 |  |  |
| [0263](https://leetcode-cn.com/problems/ugly-number) | 丑数 |  | `数学` | 简单 |  |  |
| [0264](https://leetcode-cn.com/problems/ugly-number-ii) | 丑数 II |  | `哈希表`,`数学`,`动态规划`,`堆（优先队列）` | 中等 |  |  |
| [0265](https://leetcode-cn.com/problems/paint-house-ii) | 粉刷房子 II |  | `数组`,`动态规划` | 困难 | 🔒 |  |
| [0266](https://leetcode-cn.com/problems/palindrome-permutation) | 回文排列 |  | `位运算`,`哈希表`,`字符串` | 简单 | 🔒 |  |
| [0267](https://leetcode-cn.com/problems/palindrome-permutation-ii) | 回文排列 II |  | `哈希表`,`字符串`,`回溯` | 中等 | 🔒 |  |
| [0268](https://leetcode-cn.com/problems/missing-number) | 丢失的数字 |  | `位运算`,`数组`,`哈希表`,`数学`,`排序` | 简单 |  |  |
| [0269](https://leetcode-cn.com/problems/alien-dictionary) | 火星词典 |  | `深度优先搜索`,`广度优先搜索`,`图`,`拓扑排序`,`数组`,`字符串` | 困难 | 🔒 |  |
| [0270](https://leetcode-cn.com/problems/closest-binary-search-tree-value) | 最接近的二叉搜索树值 |  | `树`,`深度优先搜索`,`二叉搜索树`,`二分查找`,`二叉树` | 简单 | 🔒 |  |
| [0271](https://leetcode-cn.com/problems/encode-and-decode-strings) | 字符串的编码与解码 |  | `设计`,`数组`,`字符串` | 中等 | 🔒 |  |
| [0272](https://leetcode-cn.com/problems/closest-binary-search-tree-value-ii) | 最接近的二叉搜索树值 II |  | `栈`,`树`,`深度优先搜索`,`二叉搜索树`,`双指针`,`二叉树`,`堆（优先队列）` | 困难 | 🔒 |  |
| [0273](https://leetcode-cn.com/problems/integer-to-english-words) | 整数转换英文表示 |  | `递归`,`数学`,`字符串` | 困难 |  |  |
| [0274](https://leetcode-cn.com/problems/h-index) | H 指数 |  | `数组`,`计数排序`,`排序` | 中等 |  |  |
| [0275](https://leetcode-cn.com/problems/h-index-ii) | H 指数 II |  | `数组`,`二分查找` | 中等 |  |  |
| [0276](https://leetcode-cn.com/problems/paint-fence) | 栅栏涂色 |  | `动态规划` | 中等 | 🔒 |  |
| [0277](https://leetcode-cn.com/problems/find-the-celebrity) | 搜寻名人 |  | `贪心`,`图`,`双指针`,`交互` | 中等 | 🔒 |  |
| [0278](https://leetcode-cn.com/problems/first-bad-version) | 第一个错误的版本 |  | `二分查找`,`交互` | 简单 |  |  |
| [0279](https://leetcode-cn.com/problems/perfect-squares) | 完全平方数 |  | `广度优先搜索`,`数学`,`动态规划` | 中等 |  |  |
| [0280](https://leetcode-cn.com/problems/wiggle-sort) | 摆动排序 |  | `贪心`,`数组`,`排序` | 中等 | 🔒 |  |
| [0281](https://leetcode-cn.com/problems/zigzag-iterator) | 锯齿迭代器 |  | `设计`,`队列`,`数组`,`迭代器` | 中等 | 🔒 |  |
| [0282](https://leetcode-cn.com/problems/expression-add-operators) | 给表达式添加运算符 |  | `数学`,`字符串`,`回溯` | 困难 |  |  |
| [0283](https://leetcode-cn.com/problems/move-zeroes) | 移动零 |  | `数组`,`双指针` | 简单 |  |  |
| [0284](https://leetcode-cn.com/problems/peeking-iterator) | 顶端迭代器 |  | `设计`,`数组`,`迭代器` | 中等 |  |  |
| [0285](https://leetcode-cn.com/problems/inorder-successor-in-bst) | 二叉搜索树中的中序后继 |  | `树`,`深度优先搜索`,`二叉搜索树`,`二叉树` | 中等 | 🔒 |  |
| [0286](https://leetcode-cn.com/problems/walls-and-gates) | 墙与门 |  | `广度优先搜索`,`数组`,`矩阵` | 中等 | 🔒 |  |
| [0287](https://leetcode-cn.com/problems/find-the-duplicate-number) | 寻找重复数 |  | `位运算`,`数组`,`双指针`,`二分查找` | 中等 |  |  |
| [0288](https://leetcode-cn.com/problems/unique-word-abbreviation) | 单词的唯一缩写 |  | `设计`,`数组`,`哈希表`,`字符串` | 中等 | 🔒 |  |
| [0289](https://leetcode-cn.com/problems/game-of-life) | 生命游戏 |  | `数组`,`矩阵`,`模拟` | 中等 |  |  |
| [0290](https://leetcode-cn.com/problems/word-pattern) | 单词规律 |  | `哈希表`,`字符串` | 简单 |  |  |
| [0291](https://leetcode-cn.com/problems/word-pattern-ii) | 单词规律 II |  | `哈希表`,`字符串`,`回溯` | 中等 | 🔒 |  |
| [0292](https://leetcode-cn.com/problems/nim-game) | Nim 游戏 |  | `脑筋急转弯`,`数学`,`博弈` | 简单 |  |  |
| [0293](https://leetcode-cn.com/problems/flip-game) | 翻转游戏 |  | `字符串` | 简单 | 🔒 |  |
| [0294](https://leetcode-cn.com/problems/flip-game-ii) | 翻转游戏 II |  | `记忆化搜索`,`数学`,`动态规划`,`回溯`,`博弈` | 中等 | 🔒 |  |
| [0295](https://leetcode-cn.com/problems/find-median-from-data-stream) | 数据流的中位数 |  | `设计`,`双指针`,`数据流`,`排序`,`堆（优先队列）` | 困难 |  |  |
| [0296](https://leetcode-cn.com/problems/best-meeting-point) | 最佳的碰头地点 |  | `数组`,`数学`,`矩阵`,`排序` | 困难 | 🔒 |  |
| [0297](https://leetcode-cn.com/problems/serialize-and-deserialize-binary-tree) | 二叉树的序列化与反序列化 |  | `树`,`深度优先搜索`,`广度优先搜索`,`设计`,`字符串`,`二叉树` | 困难 |  |  |
| [0298](https://leetcode-cn.com/problems/binary-tree-longest-consecutive-sequence) | 二叉树最长连续序列 |  | `树`,`深度优先搜索`,`二叉树` | 中等 | 🔒 |  |
| [0299](https://leetcode-cn.com/problems/bulls-and-cows) | 猜数字游戏 |  | `哈希表`,`字符串`,`计数` | 中等 |  |  |
| [0300](https://leetcode-cn.com/problems/longest-increasing-subsequence) | 最长递增子序列 |  | `数组`,`二分查找`,`动态规划` | 中等 |  |  |
| [0301](https://leetcode-cn.com/problems/remove-invalid-parentheses) | 删除无效的括号 |  | `广度优先搜索`,`字符串`,`回溯` | 困难 |  |  |
| [0302](https://leetcode-cn.com/problems/smallest-rectangle-enclosing-black-pixels) | 包含全部黑色像素的最小矩形 |  | `深度优先搜索`,`广度优先搜索`,`数组`,`二分查找`,`矩阵` | 困难 | 🔒 |  |
| [0303](https://leetcode-cn.com/problems/range-sum-query-immutable) | 区域和检索 - 数组不可变 |  | `设计`,`数组`,`前缀和` | 简单 |  |  |
| [0304](https://leetcode-cn.com/problems/range-sum-query-2d-immutable) | 二维区域和检索 - 矩阵不可变 |  | `设计`,`数组`,`矩阵`,`前缀和` | 中等 |  |  |
| [0305](https://leetcode-cn.com/problems/number-of-islands-ii) | 岛屿数量 II |  | `并查集`,`数组` | 困难 | 🔒 |  |
| [0306](https://leetcode-cn.com/problems/additive-number) | 累加数 |  | `字符串`,`回溯` | 中等 |  |  |
| [0307](https://leetcode-cn.com/problems/range-sum-query-mutable) | 区域和检索 - 数组可修改 |  | `设计`,`树状数组`,`线段树`,`数组` | 中等 |  |  |
| [0308](https://leetcode-cn.com/problems/range-sum-query-2d-mutable) | 二维区域和检索 - 可变 |  | `设计`,`树状数组`,`线段树`,`数组`,`矩阵` | 困难 | 🔒 |  |
| [0309](https://leetcode-cn.com/problems/best-time-to-buy-and-sell-stock-with-cooldown) | 最佳买卖股票时机含冷冻期 |  | `数组`,`动态规划` | 中等 |  |  |
| [0310](https://leetcode-cn.com/problems/minimum-height-trees) | 最小高度树 |  | `深度优先搜索`,`广度优先搜索`,`图`,`拓扑排序` | 中等 |  |  |
| [0311](https://leetcode-cn.com/problems/sparse-matrix-multiplication) | 稀疏矩阵的乘法 |  | `数组`,`哈希表`,`矩阵` | 中等 | 🔒 |  |
| [0312](https://leetcode-cn.com/problems/burst-balloons) | 戳气球 |  | `数组`,`动态规划` | 困难 |  |  |
| [0313](https://leetcode-cn.com/problems/super-ugly-number) | 超级丑数 |  | `数组`,`哈希表`,`数学`,`动态规划`,`堆（优先队列）` | 中等 |  |  |
| [0314](https://leetcode-cn.com/problems/binary-tree-vertical-order-traversal) | 二叉树的垂直遍历 |  | `树`,`深度优先搜索`,`广度优先搜索`,`哈希表`,`二叉树` | 中等 | 🔒 |  |
| [0315](https://leetcode-cn.com/problems/count-of-smaller-numbers-after-self) | 计算右侧小于当前元素的个数 |  | `树状数组`,`线段树`,`数组`,`二分查找`,`分治`,`有序集合`,`归并排序` | 困难 |  |  |
| [0316](https://leetcode-cn.com/problems/remove-duplicate-letters) | 去除重复字母 |  | `栈`,`贪心`,`字符串`,`单调栈` | 中等 |  |  |
| [0317](https://leetcode-cn.com/problems/shortest-distance-from-all-buildings) | 离建筑物最近的距离 |  | `广度优先搜索`,`数组`,`矩阵` | 困难 | 🔒 |  |
| [0318](https://leetcode-cn.com/problems/maximum-product-of-word-lengths) | 最大单词长度乘积 |  | `位运算`,`数组`,`字符串` | 中等 |  |  |
| [0319](https://leetcode-cn.com/problems/bulb-switcher) | 灯泡开关 |  | `脑筋急转弯`,`数学` | 中等 |  |  |
| [0320](https://leetcode-cn.com/problems/generalized-abbreviation) | 列举单词的全部缩写 |  | `位运算`,`字符串`,`回溯` | 中等 | 🔒 |  |
| [0321](https://leetcode-cn.com/problems/create-maximum-number) | 拼接最大数 |  | `栈`,`贪心`,`单调栈` | 困难 |  |  |
| [0322](https://leetcode-cn.com/problems/coin-change) | 零钱兑换 |  | `广度优先搜索`,`数组`,`动态规划` | 中等 |  |  |
| [0323](https://leetcode-cn.com/problems/number-of-connected-components-in-an-undirected-graph) | 无向图中连通分量的数目 |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`图` | 中等 | 🔒 |  |
| [0324](https://leetcode-cn.com/problems/wiggle-sort-ii) | 摆动排序 II |  | `数组`,`分治`,`快速选择`,`排序` | 中等 |  |  |
| [0325](https://leetcode-cn.com/problems/maximum-size-subarray-sum-equals-k) | 和等于 k 的最长子数组长度 |  | `数组`,`哈希表` | 中等 | 🔒 |  |
| [0326](https://leetcode-cn.com/problems/power-of-three) | 3的幂 |  | `递归`,`数学` | 简单 |  |  |
| [0327](https://leetcode-cn.com/problems/count-of-range-sum) | 区间和的个数 |  | `树状数组`,`线段树`,`数组`,`二分查找`,`分治`,`有序集合`,`归并排序` | 困难 |  |  |
| [0328](https://leetcode-cn.com/problems/odd-even-linked-list) | 奇偶链表 |  | `链表` | 中等 |  |  |
| [0329](https://leetcode-cn.com/problems/longest-increasing-path-in-a-matrix) | 矩阵中的最长递增路径 |  | `深度优先搜索`,`广度优先搜索`,`图`,`拓扑排序`,`记忆化搜索`,`动态规划` | 困难 |  |  |
| [0330](https://leetcode-cn.com/problems/patching-array) | 按要求补齐数组 |  | `贪心`,`数组` | 困难 |  |  |
| [0331](https://leetcode-cn.com/problems/verify-preorder-serialization-of-a-binary-tree) | 验证二叉树的前序序列化 |  | `栈`,`树`,`字符串`,`二叉树` | 中等 |  |  |
| [0332](https://leetcode-cn.com/problems/reconstruct-itinerary) | 重新安排行程 |  | `深度优先搜索`,`图`,`欧拉回路` | 中等 |  |  |
| [0333](https://leetcode-cn.com/problems/largest-bst-subtree) | 最大 BST 子树 |  | `树`,`深度优先搜索`,`二叉搜索树`,`动态规划`,`二叉树` | 中等 | 🔒 |  |
| [0334](https://leetcode-cn.com/problems/increasing-triplet-subsequence) | 递增的三元子序列 |  | `贪心`,`数组` | 中等 |  |  |
| [0335](https://leetcode-cn.com/problems/self-crossing) | 路径交叉 |  | `几何`,`数组`,`数学` | 困难 |  |  |
| [0336](https://leetcode-cn.com/problems/palindrome-pairs) | 回文对 |  | `字典树`,`数组`,`哈希表`,`字符串` | 困难 |  |  |
| [0337](https://leetcode-cn.com/problems/house-robber-iii) | 打家劫舍 III |  | `树`,`深度优先搜索`,`动态规划`,`二叉树` | 中等 |  |  |
| [0338](https://leetcode-cn.com/problems/counting-bits) | 比特位计数 |  | `位运算`,`动态规划` | 简单 |  |  |
| [0339](https://leetcode-cn.com/problems/nested-list-weight-sum) | 嵌套列表权重和 |  | `深度优先搜索`,`广度优先搜索` | 中等 | 🔒 |  |
| [0340](https://leetcode-cn.com/problems/longest-substring-with-at-most-k-distinct-characters) | 至多包含 K 个不同字符的最长子串 |  | `哈希表`,`字符串`,`滑动窗口` | 中等 | 🔒 |  |
| [0341](https://leetcode-cn.com/problems/flatten-nested-list-iterator) | 扁平化嵌套列表迭代器 |  | `栈`,`树`,`深度优先搜索`,`设计`,`队列`,`迭代器` | 中等 |  |  |
| [0342](https://leetcode-cn.com/problems/power-of-four) | 4的幂 |  | `位运算`,`递归`,`数学` | 简单 |  |  |
| [0343](https://leetcode-cn.com/problems/integer-break) | 整数拆分 |  | `数学`,`动态规划` | 中等 |  |  |
| [0344](https://leetcode-cn.com/problems/reverse-string) | 反转字符串 |  | `递归`,`双指针`,`字符串` | 简单 |  |  |
| [0345](https://leetcode-cn.com/problems/reverse-vowels-of-a-string) | 反转字符串中的元音字母 |  | `双指针`,`字符串` | 简单 |  | ✅ |
| [0346](https://leetcode-cn.com/problems/moving-average-from-data-stream) | 数据流中的移动平均值 |  | `设计`,`队列`,`数组`,`数据流` | 简单 | 🔒 |  |
| [0347](https://leetcode-cn.com/problems/top-k-frequent-elements) | 前 K 个高频元素 |  | `数组`,`哈希表`,`分治`,`桶排序`,`计数`,`快速选择`,`排序`,`堆（优先队列）` | 中等 |  |  |
| [0348](https://leetcode-cn.com/problems/design-tic-tac-toe) | 设计井字棋 |  | `设计`,`数组`,`哈希表`,`矩阵` | 中等 | 🔒 |  |
| [0349](https://leetcode-cn.com/problems/intersection-of-two-arrays) | 两个数组的交集 |  | `数组`,`哈希表`,`双指针`,`二分查找`,`排序` | 简单 |  |  |
| [0350](https://leetcode-cn.com/problems/intersection-of-two-arrays-ii) | 两个数组的交集 II |  | `数组`,`哈希表`,`双指针`,`二分查找`,`排序` | 简单 |  |  |
| [0351](https://leetcode-cn.com/problems/android-unlock-patterns) | 安卓系统手势解锁 |  | `动态规划`,`回溯` | 中等 | 🔒 |  |
| [0352](https://leetcode-cn.com/problems/data-stream-as-disjoint-intervals) | 将数据流变为多个不相交区间 |  | `设计`,`二分查找`,`有序集合` | 困难 |  |  |
| [0353](https://leetcode-cn.com/problems/design-snake-game) | 贪吃蛇 |  | `设计`,`队列`,`数组`,`矩阵` | 中等 | 🔒 |  |
| [0354](https://leetcode-cn.com/problems/russian-doll-envelopes) | 俄罗斯套娃信封问题 |  | `数组`,`二分查找`,`动态规划`,`排序` | 困难 |  |  |
| [0355](https://leetcode-cn.com/problems/design-twitter) | 设计推特 |  | `设计`,`哈希表`,`链表`,`堆（优先队列）` | 中等 |  |  |
| [0356](https://leetcode-cn.com/problems/line-reflection) | 直线镜像 |  | `数组`,`哈希表`,`数学` | 中等 | 🔒 |  |
| [0357](https://leetcode-cn.com/problems/count-numbers-with-unique-digits) | 计算各个位数不同的数字个数 |  | `数学`,`动态规划`,`回溯` | 中等 |  |  |
| [0358](https://leetcode-cn.com/problems/rearrange-string-k-distance-apart) | K 距离间隔重排字符串 |  | `贪心`,`哈希表`,`字符串`,`计数`,`排序`,`堆（优先队列）` | 困难 | 🔒 |  |
| [0359](https://leetcode-cn.com/problems/logger-rate-limiter) | 日志速率限制器 |  | `设计`,`哈希表` | 简单 | 🔒 |  |
| [0360](https://leetcode-cn.com/problems/sort-transformed-array) | 有序转化数组 |  | `数组`,`数学`,`双指针`,`排序` | 中等 | 🔒 |  |
| [0361](https://leetcode-cn.com/problems/bomb-enemy) | 轰炸敌人 |  | `数组`,`动态规划`,`矩阵` | 中等 | 🔒 |  |
| [0362](https://leetcode-cn.com/problems/design-hit-counter) | 敲击计数器 |  | `设计`,`队列`,`数组`,`哈希表`,`二分查找` | 中等 | 🔒 |  |
| [0363](https://leetcode-cn.com/problems/max-sum-of-rectangle-no-larger-than-k) | 矩形区域不超过 K 的最大数值和 |  | `数组`,`二分查找`,`动态规划`,`矩阵`,`有序集合` | 困难 |  |  |
| [0364](https://leetcode-cn.com/problems/nested-list-weight-sum-ii) | 加权嵌套序列和 II |  | `栈`,`深度优先搜索`,`广度优先搜索` | 中等 | 🔒 |  |
| [0365](https://leetcode-cn.com/problems/water-and-jug-problem) | 水壶问题 |  | `深度优先搜索`,`广度优先搜索`,`数学` | 中等 |  |  |
| [0366](https://leetcode-cn.com/problems/find-leaves-of-binary-tree) | 寻找二叉树的叶子节点 |  | `树`,`深度优先搜索`,`二叉树` | 中等 | 🔒 |  |
| [0367](https://leetcode-cn.com/problems/valid-perfect-square) | 有效的完全平方数 |  | `数学`,`二分查找` | 简单 |  |  |
| [0368](https://leetcode-cn.com/problems/largest-divisible-subset) | 最大整除子集 |  | `数组`,`数学`,`动态规划`,`排序` | 中等 |  |  |
| [0369](https://leetcode-cn.com/problems/plus-one-linked-list) | 给单链表加一 |  | `链表`,`数学` | 中等 | 🔒 |  |
| [0370](https://leetcode-cn.com/problems/range-addition) | 区间加法 |  | `数组`,`前缀和` | 中等 | 🔒 |  |
| [0371](https://leetcode-cn.com/problems/sum-of-two-integers) | 两整数之和 |  | `位运算`,`数学` | 中等 |  |  |
| [0372](https://leetcode-cn.com/problems/super-pow) | 超级次方 |  | `数学`,`分治` | 中等 |  |  |
| [0373](https://leetcode-cn.com/problems/find-k-pairs-with-smallest-sums) | 查找和最小的K对数字 |  | `数组`,`堆（优先队列）` | 中等 |  |  |
| [0374](https://leetcode-cn.com/problems/guess-number-higher-or-lower) | 猜数字大小 |  | `二分查找`,`交互` | 简单 |  |  |
| [0375](https://leetcode-cn.com/problems/guess-number-higher-or-lower-ii) | 猜数字大小 II |  | `数学`,`动态规划`,`博弈` | 中等 |  |  |
| [0376](https://leetcode-cn.com/problems/wiggle-subsequence) | 摆动序列 |  | `贪心`,`数组`,`动态规划` | 中等 |  |  |
| [0377](https://leetcode-cn.com/problems/combination-sum-iv) | 组合总和 Ⅳ |  | `数组`,`动态规划` | 中等 |  |  |
| [0378](https://leetcode-cn.com/problems/kth-smallest-element-in-a-sorted-matrix) | 有序矩阵中第 K 小的元素 |  | `数组`,`二分查找`,`矩阵`,`排序`,`堆（优先队列）` | 中等 |  |  |
| [0379](https://leetcode-cn.com/problems/design-phone-directory) | 电话目录管理系统 |  | `设计`,`队列`,`数组`,`哈希表`,`链表` | 中等 | 🔒 |  |
| [0380](https://leetcode-cn.com/problems/insert-delete-getrandom-o1) | O(1) 时间插入、删除和获取随机元素 |  | `设计`,`数组`,`哈希表`,`数学`,`随机化` | 中等 |  |  |
| [0381](https://leetcode-cn.com/problems/insert-delete-getrandom-o1-duplicates-allowed) | O(1) 时间插入、删除和获取随机元素 - 允许重复 |  | `设计`,`数组`,`哈希表`,`数学`,`随机化` | 困难 |  |  |
| [0382](https://leetcode-cn.com/problems/linked-list-random-node) | 链表随机节点 |  | `水塘抽样`,`链表`,`数学`,`随机化` | 中等 |  |  |
| [0383](https://leetcode-cn.com/problems/ransom-note) | 赎金信 |  | `哈希表`,`字符串`,`计数` | 简单 |  |  |
| [0384](https://leetcode-cn.com/problems/shuffle-an-array) | 打乱数组 |  | `数组`,`数学`,`随机化` | 中等 |  |  |
| [0385](https://leetcode-cn.com/problems/mini-parser) | 迷你语法分析器 |  | `栈`,`深度优先搜索`,`字符串` | 中等 |  |  |
| [0386](https://leetcode-cn.com/problems/lexicographical-numbers) | 字典序排数 |  | `深度优先搜索`,`字典树` | 中等 |  |  |
| [0387](https://leetcode-cn.com/problems/first-unique-character-in-a-string) | 字符串中的第一个唯一字符 |  | `队列`,`哈希表`,`字符串`,`计数` | 简单 |  |  |
| [0388](https://leetcode-cn.com/problems/longest-absolute-file-path) | 文件的最长绝对路径 |  | `栈`,`深度优先搜索`,`字符串` | 中等 |  |  |
| [0389](https://leetcode-cn.com/problems/find-the-difference) | 找不同 |  | `位运算`,`哈希表`,`字符串`,`排序` | 简单 |  |  |
| [0390](https://leetcode-cn.com/problems/elimination-game) | 消除游戏 |  | `数学` | 中等 |  |  |
| [0391](https://leetcode-cn.com/problems/perfect-rectangle) | 完美矩形 |  | `数组`,`扫描线` | 困难 |  |  |
| [0392](https://leetcode-cn.com/problems/is-subsequence) | 判断子序列 |  | `双指针`,`字符串`,`动态规划` | 简单 |  |  |
| [0393](https://leetcode-cn.com/problems/utf-8-validation) | UTF-8 编码验证 |  | `位运算`,`数组` | 中等 |  |  |
| [0394](https://leetcode-cn.com/problems/decode-string) | 字符串解码 |  | `栈`,`递归`,`字符串` | 中等 |  |  |
| [0395](https://leetcode-cn.com/problems/longest-substring-with-at-least-k-repeating-characters) | 至少有 K 个重复字符的最长子串 |  | `哈希表`,`字符串`,`分治`,`滑动窗口` | 中等 |  |  |
| [0396](https://leetcode-cn.com/problems/rotate-function) | 旋转函数 |  | `数学`,`动态规划` | 中等 |  |  |
| [0397](https://leetcode-cn.com/problems/integer-replacement) | 整数替换 |  | `位运算`,`记忆化搜索`,`动态规划` | 中等 |  |  |
| [0398](https://leetcode-cn.com/problems/random-pick-index) | 随机数索引 |  | `水塘抽样`,`哈希表`,`数学`,`随机化` | 中等 |  |  |
| [0399](https://leetcode-cn.com/problems/evaluate-division) | 除法求值 |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`图`,`数组`,`最短路` | 中等 |  |  |
| [0400](https://leetcode-cn.com/problems/nth-digit) | 第 N 位数字 |  | `数学`,`二分查找` | 中等 |  |  |
| [0401](https://leetcode-cn.com/problems/binary-watch) | 二进制手表 |  | `位运算`,`回溯` | 简单 |  |  |
| [0402](https://leetcode-cn.com/problems/remove-k-digits) | 移掉 K 位数字 |  | `栈`,`贪心`,`字符串`,`单调栈` | 中等 |  |  |
| [0403](https://leetcode-cn.com/problems/frog-jump) | 青蛙过河 |  | `数组`,`动态规划` | 困难 |  |  |
| [0404](https://leetcode-cn.com/problems/sum-of-left-leaves) | 左叶子之和 |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉树` | 简单 |  |  |
| [0405](https://leetcode-cn.com/problems/convert-a-number-to-hexadecimal) | 数字转换为十六进制数 |  | `位运算`,`数学` | 简单 |  |  |
| [0406](https://leetcode-cn.com/problems/queue-reconstruction-by-height) | 根据身高重建队列 |  | `贪心`,`数组`,`排序` | 中等 |  |  |
| [0407](https://leetcode-cn.com/problems/trapping-rain-water-ii) | 接雨水 II |  | `广度优先搜索`,`数组`,`矩阵`,`堆（优先队列）` | 困难 |  |  |
| [0408](https://leetcode-cn.com/problems/valid-word-abbreviation) | 有效单词缩写 |  | `双指针`,`字符串` | 简单 | 🔒 |  |
| [0409](https://leetcode-cn.com/problems/longest-palindrome) | 最长回文串 |  | `贪心`,`哈希表`,`字符串` | 简单 |  |  |
| [0410](https://leetcode-cn.com/problems/split-array-largest-sum) | 分割数组的最大值 |  | `贪心`,`数组`,`二分查找`,`动态规划` | 困难 |  |  |
| [0411](https://leetcode-cn.com/problems/minimum-unique-word-abbreviation) | 最短独占单词缩写 |  | `位运算`,`字符串`,`回溯` | 困难 | 🔒 |  |
| [0412](https://leetcode-cn.com/problems/fizz-buzz) | Fizz Buzz |  | `数学`,`字符串`,`模拟` | 简单 |  |  |
| [0413](https://leetcode-cn.com/problems/arithmetic-slices) | 等差数列划分 |  | `数组`,`动态规划` | 中等 |  |  |
| [0414](https://leetcode-cn.com/problems/third-maximum-number) | 第三大的数 |  | `数组`,`排序` | 简单 |  |  |
| [0415](https://leetcode-cn.com/problems/add-strings) | 字符串相加 |  | `数学`,`字符串`,`模拟` | 简单 |  |  |
| [0416](https://leetcode-cn.com/problems/partition-equal-subset-sum) | 分割等和子集 |  | `数组`,`动态规划` | 中等 |  |  |
| [0417](https://leetcode-cn.com/problems/pacific-atlantic-water-flow) | 太平洋大西洋水流问题 |  | `深度优先搜索`,`广度优先搜索`,`数组`,`矩阵` | 中等 |  |  |
| [0418](https://leetcode-cn.com/problems/sentence-screen-fitting) | 屏幕可显示句子的数量 |  | `字符串`,`动态规划` | 中等 | 🔒 |  |
| [0419](https://leetcode-cn.com/problems/battleships-in-a-board) | 甲板上的战舰 |  | `深度优先搜索`,`数组`,`矩阵` | 中等 |  |  |
| [0420](https://leetcode-cn.com/problems/strong-password-checker) | 强密码检验器 |  | `贪心`,`字符串`,`堆（优先队列）` | 困难 |  |  |
| [0421](https://leetcode-cn.com/problems/maximum-xor-of-two-numbers-in-an-array) | 数组中两个数的最大异或值 |  | `位运算`,`字典树`,`数组`,`哈希表` | 中等 |  |  |
| [0422](https://leetcode-cn.com/problems/valid-word-square) | 有效的单词方块 |  | `数组`,`矩阵` | 简单 | 🔒 |  |
| [0423](https://leetcode-cn.com/problems/reconstruct-original-digits-from-english) | 从英文中重建数字 |  | `哈希表`,`数学`,`字符串` | 中等 |  |  |
| [0424](https://leetcode-cn.com/problems/longest-repeating-character-replacement) | 替换后的最长重复字符 |  | `哈希表`,`字符串`,`滑动窗口` | 中等 |  |  |
| [0425](https://leetcode-cn.com/problems/word-squares) | 单词方块 |  | `字典树`,`数组`,`字符串`,`回溯` | 困难 | 🔒 |  |
| [0426](https://leetcode-cn.com/problems/convert-binary-search-tree-to-sorted-doubly-linked-list) | 将二叉搜索树转化为排序的双向链表 |  | `栈`,`树`,`深度优先搜索`,`二叉搜索树`,`链表`,`二叉树`,`双向链表` | 中等 | 🔒 |  |
| [0427](https://leetcode-cn.com/problems/construct-quad-tree) | 建立四叉树 |  | `树`,`数组`,`分治`,`矩阵` | 中等 |  |  |
| [0428](https://leetcode-cn.com/problems/serialize-and-deserialize-n-ary-tree) | 序列化和反序列化 N 叉树 |  | `树`,`深度优先搜索`,`广度优先搜索`,`字符串` | 困难 | 🔒 |  |
| [0429](https://leetcode-cn.com/problems/n-ary-tree-level-order-traversal) | N 叉树的层序遍历 |  | `树`,`广度优先搜索` | 中等 |  |  |
| [0430](https://leetcode-cn.com/problems/flatten-a-multilevel-doubly-linked-list) | 扁平化多级双向链表 |  | `深度优先搜索`,`链表`,`双向链表` | 中等 |  |  |
| [0431](https://leetcode-cn.com/problems/encode-n-ary-tree-to-binary-tree) | 将 N 叉树编码为二叉树 |  | `树`,`深度优先搜索`,`广度优先搜索`,`设计`,`二叉树` | 困难 | 🔒 |  |
| [0432](https://leetcode-cn.com/problems/all-oone-data-structure) | 全 O(1) 的数据结构 |  | `设计`,`哈希表`,`链表`,`双向链表` | 困难 |  |  |
| [0433](https://leetcode-cn.com/problems/minimum-genetic-mutation) | 最小基因变化 |  | `广度优先搜索`,`哈希表`,`字符串` | 中等 |  |  |
| [0434](https://leetcode-cn.com/problems/number-of-segments-in-a-string) | 字符串中的单词数 |  | `字符串` | 简单 |  |  |
| [0435](https://leetcode-cn.com/problems/non-overlapping-intervals) | 无重叠区间 |  | `贪心`,`数组`,`动态规划`,`排序` | 中等 |  |  |
| [0436](https://leetcode-cn.com/problems/find-right-interval) | 寻找右区间 |  | `数组`,`二分查找`,`排序` | 中等 |  |  |
| [0437](https://leetcode-cn.com/problems/path-sum-iii) | 路径总和 III |  | `树`,`深度优先搜索`,`二叉树` | 中等 |  |  |
| [0438](https://leetcode-cn.com/problems/find-all-anagrams-in-a-string) | 找到字符串中所有字母异位词 |  | `哈希表`,`字符串`,`滑动窗口` | 中等 |  |  |
| [0439](https://leetcode-cn.com/problems/ternary-expression-parser) | 三元表达式解析器 |  | `栈`,`递归`,`字符串` | 中等 | 🔒 |  |
| [0440](https://leetcode-cn.com/problems/k-th-smallest-in-lexicographical-order) | 字典序的第K小数字 |  | `字典树` | 困难 |  |  |
| [0441](https://leetcode-cn.com/problems/arranging-coins) | 排列硬币 |  | `数学`,`二分查找` | 简单 |  |  |
| [0442](https://leetcode-cn.com/problems/find-all-duplicates-in-an-array) | 数组中重复的数据 |  | `数组`,`哈希表` | 中等 |  |  |
| [0443](https://leetcode-cn.com/problems/string-compression) | 压缩字符串 |  | `双指针`,`字符串` | 中等 |  |  |
| [0444](https://leetcode-cn.com/problems/sequence-reconstruction) | 序列重建 |  | `图`,`拓扑排序`,`数组` | 中等 | 🔒 |  |
| [0445](https://leetcode-cn.com/problems/add-two-numbers-ii) | 两数相加 II |  | `栈`,`链表`,`数学` | 中等 |  |  |
| [0446](https://leetcode-cn.com/problems/arithmetic-slices-ii-subsequence) | 等差数列划分 II - 子序列 |  | `数组`,`动态规划` | 困难 |  |  |
| [0447](https://leetcode-cn.com/problems/number-of-boomerangs) | 回旋镖的数量 |  | `数组`,`哈希表`,`数学` | 中等 |  |  |
| [0448](https://leetcode-cn.com/problems/find-all-numbers-disappeared-in-an-array) | 找到所有数组中消失的数字 |  | `数组`,`哈希表` | 简单 |  |  |
| [0449](https://leetcode-cn.com/problems/serialize-and-deserialize-bst) | 序列化和反序列化二叉搜索树 |  | `树`,`深度优先搜索`,`广度优先搜索`,`设计`,`二叉搜索树`,`字符串`,`二叉树` | 中等 |  |  |
| [0450](https://leetcode-cn.com/problems/delete-node-in-a-bst) | 删除二叉搜索树中的节点 |  | `树`,`二叉搜索树`,`二叉树` | 中等 |  |  |
| [0451](https://leetcode-cn.com/problems/sort-characters-by-frequency) | 根据字符出现频率排序 |  | `哈希表`,`字符串`,`桶排序`,`计数`,`排序`,`堆（优先队列）` | 中等 |  |  |
| [0452](https://leetcode-cn.com/problems/minimum-number-of-arrows-to-burst-balloons) | 用最少数量的箭引爆气球 |  | `贪心`,`数组`,`排序` | 中等 |  |  |
| [0453](https://leetcode-cn.com/problems/minimum-moves-to-equal-array-elements) | 最小操作次数使数组元素相等 |  | `数组`,`数学` | 简单 |  |  |
| [0454](https://leetcode-cn.com/problems/4sum-ii) | 四数相加 II |  | `数组`,`哈希表` | 中等 |  |  |
| [0455](https://leetcode-cn.com/problems/assign-cookies) | 分发饼干 |  | `贪心`,`数组`,`排序` | 简单 |  |  |
| [0456](https://leetcode-cn.com/problems/132-pattern) | 132 模式 |  | `栈`,`数组`,`二分查找`,`有序集合`,`单调栈` | 中等 |  |  |
| [0457](https://leetcode-cn.com/problems/circular-array-loop) | 环形数组是否存在循环 |  | `数组`,`哈希表`,`双指针` | 中等 |  |  |
| [0458](https://leetcode-cn.com/problems/poor-pigs) | 可怜的小猪 |  | `数学`,`动态规划`,`组合数学` | 困难 |  |  |
| [0459](https://leetcode-cn.com/problems/repeated-substring-pattern) | 重复的子字符串 |  | `字符串`,`字符串匹配` | 简单 |  |  |
| [0460](https://leetcode-cn.com/problems/lfu-cache) | LFU 缓存 |  | `设计`,`哈希表`,`链表`,`双向链表` | 困难 |  |  |
| [0461](https://leetcode-cn.com/problems/hamming-distance) | 汉明距离 |  | `位运算` | 简单 |  |  |
| [0462](https://leetcode-cn.com/problems/minimum-moves-to-equal-array-elements-ii) | 最少移动次数使数组元素相等 II |  | `数组`,`数学`,`排序` | 中等 |  |  |
| [0463](https://leetcode-cn.com/problems/island-perimeter) | 岛屿的周长 |  | `深度优先搜索`,`广度优先搜索`,`数组`,`矩阵` | 简单 |  |  |
| [0464](https://leetcode-cn.com/problems/can-i-win) | 我能赢吗 |  | `位运算`,`记忆化搜索`,`数学`,`动态规划`,`状态压缩`,`博弈` | 中等 |  |  |
| [0465](https://leetcode-cn.com/problems/optimal-account-balancing) | 最优账单平衡 |  | `数组`,`回溯` | 困难 | 🔒 |  |
| [0466](https://leetcode-cn.com/problems/count-the-repetitions) | 统计重复个数 |  | `字符串`,`动态规划` | 困难 |  |  |
| [0467](https://leetcode-cn.com/problems/unique-substrings-in-wraparound-string) | 环绕字符串中唯一的子字符串 |  | `字符串`,`动态规划` | 中等 |  |  |
| [0468](https://leetcode-cn.com/problems/validate-ip-address) | 验证IP地址 |  | `字符串` | 中等 |  |  |
| [0469](https://leetcode-cn.com/problems/convex-polygon) | 凸多边形 |  | `几何`,`数学` | 中等 | 🔒 |  |
| [0470](https://leetcode-cn.com/problems/implement-rand10-using-rand7) | 用 Rand7() 实现 Rand10() |  | `数学`,`拒绝采样`,`概率与统计`,`随机化` | 中等 |  |  |
| [0471](https://leetcode-cn.com/problems/encode-string-with-shortest-length) | 编码最短长度的字符串 |  | `字符串`,`动态规划` | 困难 | 🔒 |  |
| [0472](https://leetcode-cn.com/problems/concatenated-words) | 连接词 |  | `深度优先搜索`,`字典树`,`字符串`,`动态规划` | 困难 |  |  |
| [0473](https://leetcode-cn.com/problems/matchsticks-to-square) | 火柴拼正方形 |  | `位运算`,`数组`,`动态规划`,`回溯`,`状态压缩` | 中等 |  |  |
| [0474](https://leetcode-cn.com/problems/ones-and-zeroes) | 一和零 |  | `数组`,`字符串`,`动态规划` | 中等 |  |  |
| [0475](https://leetcode-cn.com/problems/heaters) | 供暖器 |  | `数组`,`二分查找`,`排序` | 中等 |  |  |
| [0476](https://leetcode-cn.com/problems/number-complement) | 数字的补数 |  | `位运算` | 简单 |  |  |
| [0477](https://leetcode-cn.com/problems/total-hamming-distance) | 汉明距离总和 |  | `位运算`,`数组`,`数学` | 中等 |  |  |
| [0478](https://leetcode-cn.com/problems/generate-random-point-in-a-circle) | 在圆内随机生成点 |  | `几何`,`数学`,`拒绝采样`,`随机化` | 中等 |  |  |
| [0479](https://leetcode-cn.com/problems/largest-palindrome-product) | 最大回文数乘积 |  | `数学` | 困难 |  |  |
| [0480](https://leetcode-cn.com/problems/sliding-window-median) | 滑动窗口中位数 |  | `数组`,`哈希表`,`滑动窗口`,`堆（优先队列）` | 困难 |  |  |
| [0481](https://leetcode-cn.com/problems/magical-string) | 神奇字符串 |  | `双指针`,`字符串` | 中等 |  |  |
| [0482](https://leetcode-cn.com/problems/license-key-formatting) | 密钥格式化 |  | `字符串` | 简单 |  |  |
| [0483](https://leetcode-cn.com/problems/smallest-good-base) | 最小好进制 |  | `数学`,`二分查找` | 困难 |  |  |
| [0484](https://leetcode-cn.com/problems/find-permutation) | 寻找排列 |  | `栈`,`贪心`,`数组` | 中等 | 🔒 |  |
| [0485](https://leetcode-cn.com/problems/max-consecutive-ones) | 最大连续 1 的个数 |  | `数组` | 简单 |  |  |
| [0486](https://leetcode-cn.com/problems/predict-the-winner) | 预测赢家 |  | `递归`,`数组`,`数学`,`动态规划`,`博弈` | 中等 |  |  |
| [0487](https://leetcode-cn.com/problems/max-consecutive-ones-ii) | 最大连续1的个数 II |  | `数组`,`动态规划`,`滑动窗口` | 中等 | 🔒 |  |
| [0488](https://leetcode-cn.com/problems/zuma-game) | 祖玛游戏 |  | `字符串`,`回溯` | 困难 |  |  |
| [0489](https://leetcode-cn.com/problems/robot-room-cleaner) | 扫地机器人 |  | `回溯`,`交互` | 困难 | 🔒 |  |
| [0490](https://leetcode-cn.com/problems/the-maze) | 迷宫 |  | `深度优先搜索`,`广度优先搜索`,`图` | 中等 | 🔒 |  |
| [0491](https://leetcode-cn.com/problems/increasing-subsequences) | 递增子序列 |  | `位运算`,`数组`,`哈希表`,`回溯` | 中等 |  |  |
| [0492](https://leetcode-cn.com/problems/construct-the-rectangle) | 构造矩形 |  | `数学` | 简单 |  |  |
| [0493](https://leetcode-cn.com/problems/reverse-pairs) | 翻转对 |  | `树状数组`,`线段树`,`数组`,`二分查找`,`分治`,`有序集合`,`归并排序` | 困难 |  |  |
| [0494](https://leetcode-cn.com/problems/target-sum) | 目标和 |  | `数组`,`动态规划`,`回溯` | 中等 |  |  |
| [0495](https://leetcode-cn.com/problems/teemo-attacking) | 提莫攻击 |  | `数组`,`模拟` | 简单 |  |  |
| [0496](https://leetcode-cn.com/problems/next-greater-element-i) | 下一个更大元素 I |  | `栈`,`数组`,`哈希表`,`单调栈` | 简单 |  |  |
| [0497](https://leetcode-cn.com/problems/random-point-in-non-overlapping-rectangles) | 非重叠矩形中的随机点 |  | `水塘抽样`,`数学`,`二分查找`,`有序集合`,`前缀和`,`随机化` | 中等 |  |  |
| [0498](https://leetcode-cn.com/problems/diagonal-traverse) | 对角线遍历 |  | `数组`,`矩阵`,`模拟` | 中等 |  |  |
| [0499](https://leetcode-cn.com/problems/the-maze-iii) | 迷宫 III |  | `深度优先搜索`,`广度优先搜索`,`图`,`最短路`,`堆（优先队列）` | 困难 | 🔒 |  |
| [0500](https://leetcode-cn.com/problems/keyboard-row) | 键盘行 |  | `数组`,`哈希表`,`字符串` | 简单 |  |  |
| [0501](https://leetcode-cn.com/problems/find-mode-in-binary-search-tree) | 二叉搜索树中的众数 |  | `树`,`深度优先搜索`,`二叉搜索树`,`二叉树` | 简单 |  |  |
| [0502](https://leetcode-cn.com/problems/ipo) | IPO |  | `贪心`,`数组`,`排序`,`堆（优先队列）` | 困难 |  |  |
| [0503](https://leetcode-cn.com/problems/next-greater-element-ii) | 下一个更大元素 II |  | `栈`,`数组`,`单调栈` | 中等 |  |  |
| [0504](https://leetcode-cn.com/problems/base-7) | 七进制数 |  | `数学` | 简单 |  |  |
| [0505](https://leetcode-cn.com/problems/the-maze-ii) | 迷宫 II |  | `深度优先搜索`,`广度优先搜索`,`图`,`最短路`,`堆（优先队列）` | 中等 | 🔒 |  |
| [0506](https://leetcode-cn.com/problems/relative-ranks) | 相对名次 |  | `数组`,`排序`,`堆（优先队列）` | 简单 |  |  |
| [0507](https://leetcode-cn.com/problems/perfect-number) | 完美数 |  | `数学` | 简单 |  |  |
| [0508](https://leetcode-cn.com/problems/most-frequent-subtree-sum) | 出现次数最多的子树元素和 |  | `树`,`深度优先搜索`,`哈希表`,`二叉树` | 中等 |  |  |
| [0509](https://leetcode-cn.com/problems/fibonacci-number) | 斐波那契数 |  | `递归`,`记忆化搜索`,`数学`,`动态规划` | 简单 |  |  |
| [0510](https://leetcode-cn.com/problems/inorder-successor-in-bst-ii) | 二叉搜索树中的中序后继 II |  | `树`,`二叉搜索树`,`二叉树` | 中等 | 🔒 |  |
| [0511](https://leetcode-cn.com/problems/game-play-analysis-i) | 游戏玩法分析 I |  | `数据库` | 简单 | 🔒 |  |
| [0512](https://leetcode-cn.com/problems/game-play-analysis-ii) | 游戏玩法分析 II |  | `数据库` | 简单 | 🔒 |  |
| [0513](https://leetcode-cn.com/problems/find-bottom-left-tree-value) | 找树左下角的值 |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉树` | 中等 |  |  |
| [0514](https://leetcode-cn.com/problems/freedom-trail) | 自由之路 |  | `深度优先搜索`,`广度优先搜索`,`字符串`,`动态规划` | 困难 |  |  |
| [0515](https://leetcode-cn.com/problems/find-largest-value-in-each-tree-row) | 在每个树行中找最大值 |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉树` | 中等 |  |  |
| [0516](https://leetcode-cn.com/problems/longest-palindromic-subsequence) | 最长回文子序列 |  | `字符串`,`动态规划` | 中等 |  |  |
| [0517](https://leetcode-cn.com/problems/super-washing-machines) | 超级洗衣机 |  | `贪心`,`数组` | 困难 |  |  |
| [0518](https://leetcode-cn.com/problems/coin-change-2) | 零钱兑换 II |  | `数组`,`动态规划` | 中等 |  |  |
| [0519](https://leetcode-cn.com/problems/random-flip-matrix) | 随机翻转矩阵 |  | `水塘抽样`,`哈希表`,`数学`,`随机化` | 中等 |  |  |
| [0520](https://leetcode-cn.com/problems/detect-capital) | 检测大写字母 |  | `字符串` | 简单 |  |  |
| [0521](https://leetcode-cn.com/problems/longest-uncommon-subsequence-i) | 最长特殊序列 Ⅰ |  | `字符串` | 简单 |  |  |
| [0522](https://leetcode-cn.com/problems/longest-uncommon-subsequence-ii) | 最长特殊序列 II |  | `数组`,`哈希表`,`双指针`,`字符串`,`排序` | 中等 |  |  |
| [0523](https://leetcode-cn.com/problems/continuous-subarray-sum) | 连续的子数组和 |  | `数组`,`哈希表`,`数学`,`前缀和` | 中等 |  |  |
| [0524](https://leetcode-cn.com/problems/longest-word-in-dictionary-through-deleting) | 通过删除字母匹配到字典里最长单词 |  | `数组`,`双指针`,`字符串`,`排序` | 中等 |  |  |
| [0525](https://leetcode-cn.com/problems/contiguous-array) | 连续数组 |  | `数组`,`哈希表`,`前缀和` | 中等 |  |  |
| [0526](https://leetcode-cn.com/problems/beautiful-arrangement) | 优美的排列 |  | `位运算`,`数组`,`动态规划`,`回溯`,`状态压缩` | 中等 |  |  |
| [0527](https://leetcode-cn.com/problems/word-abbreviation) | 单词缩写 |  | `贪心`,`字典树`,`数组`,`字符串`,`排序` | 困难 | 🔒 |  |
| [0528](https://leetcode-cn.com/problems/random-pick-with-weight) | 按权重随机选择 |  | `数学`,`二分查找`,`前缀和`,`随机化` | 中等 |  |  |
| [0529](https://leetcode-cn.com/problems/minesweeper) | 扫雷游戏 |  | `深度优先搜索`,`广度优先搜索`,`数组`,`矩阵` | 中等 |  |  |
| [0530](https://leetcode-cn.com/problems/minimum-absolute-difference-in-bst) | 二叉搜索树的最小绝对差 |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉搜索树`,`二叉树` | 简单 |  |  |
| [0531](https://leetcode-cn.com/problems/lonely-pixel-i) | 孤独像素 I |  | `数组`,`哈希表`,`矩阵` | 中等 | 🔒 |  |
| [0532](https://leetcode-cn.com/problems/k-diff-pairs-in-an-array) | 数组中的 k-diff 数对 |  | `数组`,`哈希表`,`双指针`,`二分查找`,`排序` | 中等 |  |  |
| [0533](https://leetcode-cn.com/problems/lonely-pixel-ii) | 孤独像素 II |  | `数组`,`哈希表`,`矩阵` | 中等 | 🔒 |  |
| [0534](https://leetcode-cn.com/problems/game-play-analysis-iii) | 游戏玩法分析 III |  | `数据库` | 中等 | 🔒 |  |
| [0535](https://leetcode-cn.com/problems/encode-and-decode-tinyurl) | TinyURL 的加密与解密 |  | `设计`,`哈希表`,`字符串`,`哈希函数` | 中等 |  |  |
| [0536](https://leetcode-cn.com/problems/construct-binary-tree-from-string) | 从字符串生成二叉树 |  | `树`,`深度优先搜索`,`字符串`,`二叉树` | 中等 | 🔒 |  |
| [0537](https://leetcode-cn.com/problems/complex-number-multiplication) | 复数乘法 |  | `数学`,`字符串`,`模拟` | 中等 |  |  |
| [0538](https://leetcode-cn.com/problems/convert-bst-to-greater-tree) | 把二叉搜索树转换为累加树 |  | `树`,`深度优先搜索`,`二叉搜索树`,`二叉树` | 中等 |  |  |
| [0539](https://leetcode-cn.com/problems/minimum-time-difference) | 最小时间差 |  | `数组`,`数学`,`字符串`,`排序` | 中等 |  |  |
| [0540](https://leetcode-cn.com/problems/single-element-in-a-sorted-array) | 有序数组中的单一元素 |  | `数组`,`二分查找` | 中等 |  |  |
| [0541](https://leetcode-cn.com/problems/reverse-string-ii) | 反转字符串 II |  | `双指针`,`字符串` | 简单 |  |  |
| [0542](https://leetcode-cn.com/problems/01-matrix) | 01 矩阵 |  | `广度优先搜索`,`数组`,`动态规划`,`矩阵` | 中等 |  |  |
| [0543](https://leetcode-cn.com/problems/diameter-of-binary-tree) | 二叉树的直径 |  | `树`,`深度优先搜索`,`二叉树` | 简单 |  |  |
| [0544](https://leetcode-cn.com/problems/output-contest-matches) | 输出比赛匹配对 |  | `递归`,`字符串`,`模拟` | 中等 | 🔒 |  |
| [0545](https://leetcode-cn.com/problems/boundary-of-binary-tree) | 二叉树的边界 |  | `树`,`深度优先搜索`,`二叉树` | 中等 | 🔒 |  |
| [0546](https://leetcode-cn.com/problems/remove-boxes) | 移除盒子 |  | `记忆化搜索`,`数组`,`动态规划` | 困难 |  |  |
| [0547](https://leetcode-cn.com/problems/number-of-provinces) | 省份数量 |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`图` | 中等 |  |  |
| [0548](https://leetcode-cn.com/problems/split-array-with-equal-sum) | 将数组分割成和相等的子数组 |  | `数组`,`前缀和` | 困难 | 🔒 |  |
| [0549](https://leetcode-cn.com/problems/binary-tree-longest-consecutive-sequence-ii) | 二叉树中最长的连续序列 |  | `树`,`深度优先搜索`,`二叉树` | 中等 | 🔒 |  |
| [0550](https://leetcode-cn.com/problems/game-play-analysis-iv) | 游戏玩法分析 IV |  | `数据库` | 中等 | 🔒 |  |
| [0551](https://leetcode-cn.com/problems/student-attendance-record-i) | 学生出勤记录 I |  | `字符串` | 简单 |  |  |
| [0552](https://leetcode-cn.com/problems/student-attendance-record-ii) | 学生出勤记录 II |  | `动态规划` | 困难 |  |  |
| [0553](https://leetcode-cn.com/problems/optimal-division) | 最优除法 |  | `数组`,`数学`,`动态规划` | 中等 |  |  |
| [0554](https://leetcode-cn.com/problems/brick-wall) | 砖墙 |  | `数组`,`哈希表` | 中等 |  |  |
| [0555](https://leetcode-cn.com/problems/split-concatenated-strings) | 分割连接字符串 |  | `贪心`,`数组`,`字符串` | 中等 | 🔒 |  |
| [0556](https://leetcode-cn.com/problems/next-greater-element-iii) | 下一个更大元素 III |  | `数学`,`双指针`,`字符串` | 中等 |  |  |
| [0557](https://leetcode-cn.com/problems/reverse-words-in-a-string-iii) | 反转字符串中的单词 III |  | `双指针`,`字符串` | 简单 |  |  |
| [0558](https://leetcode-cn.com/problems/logical-or-of-two-binary-grids-represented-as-quad-trees) | 四叉树交集 |  | `树`,`分治` | 中等 |  |  |
| [0559](https://leetcode-cn.com/problems/maximum-depth-of-n-ary-tree) | N 叉树的最大深度 |  | `树`,`深度优先搜索`,`广度优先搜索` | 简单 |  |  |
| [0560](https://leetcode-cn.com/problems/subarray-sum-equals-k) | 和为K的子数组 |  | `数组`,`哈希表`,`前缀和` | 中等 |  |  |
| [0561](https://leetcode-cn.com/problems/array-partition-i) | 数组拆分 I |  | `贪心`,`数组`,`计数排序`,`排序` | 简单 |  |  |
| [0562](https://leetcode-cn.com/problems/longest-line-of-consecutive-one-in-matrix) | 矩阵中最长的连续1线段 |  | `数组`,`动态规划`,`矩阵` | 中等 | 🔒 |  |
| [0563](https://leetcode-cn.com/problems/binary-tree-tilt) | 二叉树的坡度 |  | `树`,`深度优先搜索`,`二叉树` | 简单 |  |  |
| [0564](https://leetcode-cn.com/problems/find-the-closest-palindrome) | 寻找最近的回文数 |  | `数学`,`字符串` | 困难 |  |  |
| [0565](https://leetcode-cn.com/problems/array-nesting) | 数组嵌套 |  | `深度优先搜索`,`数组` | 中等 |  |  |
| [0566](https://leetcode-cn.com/problems/reshape-the-matrix) | 重塑矩阵 |  | `数组`,`矩阵`,`模拟` | 简单 |  |  |
| [0567](https://leetcode-cn.com/problems/permutation-in-string) | 字符串的排列 |  | `哈希表`,`双指针`,`字符串`,`滑动窗口` | 中等 |  |  |
| [0568](https://leetcode-cn.com/problems/maximum-vacation-days) | 最大休假天数 |  | `数组`,`动态规划`,`矩阵` | 困难 | 🔒 |  |
| [0569](https://leetcode-cn.com/problems/median-employee-salary) | 员工薪水中位数 |  | `数据库` | 困难 | 🔒 |  |
| [0570](https://leetcode-cn.com/problems/managers-with-at-least-5-direct-reports) | 至少有5名直接下属的经理 |  | `数据库` | 中等 | 🔒 |  |
| [0571](https://leetcode-cn.com/problems/find-median-given-frequency-of-numbers) | 给定数字的频率查询中位数 |  | `数据库` | 困难 | 🔒 |  |
| [0572](https://leetcode-cn.com/problems/subtree-of-another-tree) | 另一棵树的子树 |  | `树`,`深度优先搜索`,`二叉树`,`字符串匹配`,`哈希函数` | 简单 |  |  |
| [0573](https://leetcode-cn.com/problems/squirrel-simulation) | 松鼠模拟 |  | `数组`,`数学` | 中等 | 🔒 |  |
| [0574](https://leetcode-cn.com/problems/winning-candidate) | 当选者 |  | `数据库` | 中等 | 🔒 |  |
| [0575](https://leetcode-cn.com/problems/distribute-candies) | 分糖果 |  | `数组`,`哈希表` | 简单 |  |  |
| [0576](https://leetcode-cn.com/problems/out-of-boundary-paths) | 出界的路径数 |  | `动态规划` | 中等 |  |  |
| [0577](https://leetcode-cn.com/problems/employee-bonus) | 员工奖金 |  | `数据库` | 简单 | 🔒 |  |
| [0578](https://leetcode-cn.com/problems/get-highest-answer-rate-question) | 查询回答率最高的问题 |  | `数据库` | 中等 | 🔒 |  |
| [0579](https://leetcode-cn.com/problems/find-cumulative-salary-of-an-employee) | 查询员工的累计薪水 |  | `数据库` | 困难 | 🔒 |  |
| [0580](https://leetcode-cn.com/problems/count-student-number-in-departments) | 统计各专业学生人数 |  | `数据库` | 中等 | 🔒 |  |
| [0581](https://leetcode-cn.com/problems/shortest-unsorted-continuous-subarray) | 最短无序连续子数组 |  | `栈`,`贪心`,`数组`,`双指针`,`排序`,`单调栈` | 中等 |  |  |
| [0582](https://leetcode-cn.com/problems/kill-process) | 杀掉进程 |  | `树`,`深度优先搜索`,`广度优先搜索`,`数组`,`哈希表` | 中等 | 🔒 |  |
| [0583](https://leetcode-cn.com/problems/delete-operation-for-two-strings) | 两个字符串的删除操作 |  | `字符串`,`动态规划` | 中等 |  |  |
| [0584](https://leetcode-cn.com/problems/find-customer-referee) | 寻找用户推荐人 |  | `数据库` | 简单 | 🔒 |  |
| [0585](https://leetcode-cn.com/problems/investments-in-2016) | 2016年的投资 |  | `数据库` | 中等 | 🔒 |  |
| [0586](https://leetcode-cn.com/problems/customer-placing-the-largest-number-of-orders) | 订单最多的客户 |  | `数据库` | 简单 | 🔒 |  |
| [0587](https://leetcode-cn.com/problems/erect-the-fence) | 安装栅栏 |  | `几何`,`数组`,`数学` | 困难 |  |  |
| [0588](https://leetcode-cn.com/problems/design-in-memory-file-system) | 设计内存文件系统 |  | `设计`,`字典树`,`哈希表`,`字符串` | 困难 | 🔒 |  |
| [0589](https://leetcode-cn.com/problems/n-ary-tree-preorder-traversal) | N 叉树的前序遍历 |  | `栈`,`树`,`深度优先搜索` | 简单 |  |  |
| [0590](https://leetcode-cn.com/problems/n-ary-tree-postorder-traversal) | N 叉树的后序遍历 |  | `栈`,`树`,`深度优先搜索` | 简单 |  |  |
| [0591](https://leetcode-cn.com/problems/tag-validator) | 标签验证器 |  | `栈`,`字符串` | 困难 |  |  |
| [0592](https://leetcode-cn.com/problems/fraction-addition-and-subtraction) | 分数加减运算 |  | `数学`,`字符串`,`模拟` | 中等 |  |  |
| [0593](https://leetcode-cn.com/problems/valid-square) | 有效的正方形 |  | `几何`,`数学` | 中等 |  | ✅ |
| [0594](https://leetcode-cn.com/problems/longest-harmonious-subsequence) | 最长和谐子序列 |  | `数组`,`哈希表`,`排序` | 简单 |  |  |
| [0595](https://leetcode-cn.com/problems/big-countries) | 大的国家 |  | `数据库` | 简单 |  |  |
| [0596](https://leetcode-cn.com/problems/classes-more-than-5-students) | 超过5名学生的课 |  | `数据库` | 简单 |  |  |
| [0597](https://leetcode-cn.com/problems/friend-requests-i-overall-acceptance-rate) | 好友申请 I：总体通过率 |  | `数据库` | 简单 | 🔒 |  |
| [0598](https://leetcode-cn.com/problems/range-addition-ii) | 范围求和 II |  | `数组`,`数学` | 简单 |  |  |
| [0599](https://leetcode-cn.com/problems/minimum-index-sum-of-two-lists) | 两个列表的最小索引总和 |  | `数组`,`哈希表`,`字符串` | 简单 |  |  |
| [0600](https://leetcode-cn.com/problems/non-negative-integers-without-consecutive-ones) | 不含连续1的非负整数 |  | `动态规划` | 困难 |  |  |
| [0601](https://leetcode-cn.com/problems/human-traffic-of-stadium) | 体育馆的人流量 |  | `数据库` | 困难 |  |  |
| [0602](https://leetcode-cn.com/problems/friend-requests-ii-who-has-the-most-friends) | 好友申请 II ：谁有最多的好友 |  | `数据库` | 中等 | 🔒 |  |
| [0603](https://leetcode-cn.com/problems/consecutive-available-seats) | 连续空余座位 |  | `数据库` | 简单 | 🔒 |  |
| [0604](https://leetcode-cn.com/problems/design-compressed-string-iterator) | 迭代压缩字符串 |  | `设计`,`数组`,`哈希表`,`字符串`,`迭代器` | 简单 | 🔒 |  |
| [0605](https://leetcode-cn.com/problems/can-place-flowers) | 种花问题 |  | `贪心`,`数组` | 简单 |  |  |
| [0606](https://leetcode-cn.com/problems/construct-string-from-binary-tree) | 根据二叉树创建字符串 |  | `树`,`深度优先搜索`,`字符串`,`二叉树` | 简单 |  |  |
| [0607](https://leetcode-cn.com/problems/sales-person) | 销售员 |  | `数据库` | 简单 | 🔒 |  |
| [0608](https://leetcode-cn.com/problems/tree-node) | 树节点 |  | `数据库` | 中等 | 🔒 |  |
| [0609](https://leetcode-cn.com/problems/find-duplicate-file-in-system) | 在系统中查找重复文件 |  | `数组`,`哈希表`,`字符串` | 中等 |  |  |
| [0610](https://leetcode-cn.com/problems/triangle-judgement) | 判断三角形 |  | `数据库` | 简单 | 🔒 |  |
| [0611](https://leetcode-cn.com/problems/valid-triangle-number) | 有效三角形的个数 |  | `贪心`,`数组`,`双指针`,`二分查找`,`排序` | 中等 |  |  |
| [0612](https://leetcode-cn.com/problems/shortest-distance-in-a-plane) | 平面上的最近距离 |  | `数据库` | 中等 | 🔒 |  |
| [0613](https://leetcode-cn.com/problems/shortest-distance-in-a-line) | 直线上的最近距离 |  | `数据库` | 简单 | 🔒 |  |
| [0614](https://leetcode-cn.com/problems/second-degree-follower) | 二级关注者 |  | `数据库` | 中等 | 🔒 |  |
| [0615](https://leetcode-cn.com/problems/average-salary-departments-vs-company) | 平均工资：部门与公司比较 |  | `数据库` | 困难 | 🔒 |  |
| [0616](https://leetcode-cn.com/problems/add-bold-tag-in-string) | 给字符串添加加粗标签 |  | `字典树`,`数组`,`哈希表`,`字符串`,`字符串匹配` | 中等 | 🔒 |  |
| [0617](https://leetcode-cn.com/problems/merge-two-binary-trees) | 合并二叉树 |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉树` | 简单 |  |  |
| [0618](https://leetcode-cn.com/problems/students-report-by-geography) | 学生地理信息报告 |  | `数据库` | 困难 | 🔒 |  |
| [0619](https://leetcode-cn.com/problems/biggest-single-number) | 只出现一次的最大数字 |  | `数据库` | 简单 | 🔒 |  |
| [0620](https://leetcode-cn.com/problems/not-boring-movies) | 有趣的电影 |  | `数据库` | 简单 |  |  |
| [0621](https://leetcode-cn.com/problems/task-scheduler) | 任务调度器 |  | `贪心`,`数组`,`哈希表`,`计数`,`排序`,`堆（优先队列）` | 中等 |  |  |
| [0622](https://leetcode-cn.com/problems/design-circular-queue) | 设计循环队列 |  | `设计`,`队列`,`数组`,`链表` | 中等 |  |  |
| [0623](https://leetcode-cn.com/problems/add-one-row-to-tree) | 在二叉树中增加一行 |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉树` | 中等 |  |  |
| [0624](https://leetcode-cn.com/problems/maximum-distance-in-arrays) | 数组列表中的最大距离 |  | `贪心`,`数组` | 中等 | 🔒 |  |
| [0625](https://leetcode-cn.com/problems/minimum-factorization) | 最小因式分解 |  | `贪心`,`数学` | 中等 | 🔒 |  |
| [0626](https://leetcode-cn.com/problems/exchange-seats) | 换座位 |  | `数据库` | 中等 |  |  |
| [0627](https://leetcode-cn.com/problems/swap-salary) | 变更性别 |  | `数据库` | 简单 |  |  |
| [0628](https://leetcode-cn.com/problems/maximum-product-of-three-numbers) | 三个数的最大乘积 |  | `数组`,`数学`,`排序` | 简单 |  |  |
| [0629](https://leetcode-cn.com/problems/k-inverse-pairs-array) | K个逆序对数组 |  | `动态规划` | 困难 |  |  |
| [0630](https://leetcode-cn.com/problems/course-schedule-iii) | 课程表 III |  | `贪心`,`数组`,`堆（优先队列）` | 困难 |  |  |
| [0631](https://leetcode-cn.com/problems/design-excel-sum-formula) | 设计 Excel 求和公式 |  | `图`,`设计`,`拓扑排序` | 困难 | 🔒 |  |
| [0632](https://leetcode-cn.com/problems/smallest-range-covering-elements-from-k-lists) | 最小区间 |  | `贪心`,`数组`,`哈希表`,`排序`,`滑动窗口`,`堆（优先队列）` | 困难 |  |  |
| [0633](https://leetcode-cn.com/problems/sum-of-square-numbers) | 平方数之和 |  | `数学`,`双指针`,`二分查找` | 中等 |  | ✅ |
| [0634](https://leetcode-cn.com/problems/find-the-derangement-of-an-array) | 寻找数组的错位排列 |  | `数学`,`动态规划` | 中等 | 🔒 |  |
| [0635](https://leetcode-cn.com/problems/design-log-storage-system) | 设计日志存储系统 |  | `设计`,`哈希表`,`字符串`,`有序集合` | 中等 | 🔒 |  |
| [0636](https://leetcode-cn.com/problems/exclusive-time-of-functions) | 函数的独占时间 |  | `栈`,`数组` | 中等 |  |  |
| [0637](https://leetcode-cn.com/problems/average-of-levels-in-binary-tree) | 二叉树的层平均值 |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉树` | 简单 |  |  |
| [0638](https://leetcode-cn.com/problems/shopping-offers) | 大礼包 |  | `位运算`,`记忆化搜索`,`数组`,`动态规划`,`回溯`,`状态压缩` | 中等 |  |  |
| [0639](https://leetcode-cn.com/problems/decode-ways-ii) | 解码方法 II |  | `字符串`,`动态规划` | 困难 |  |  |
| [0640](https://leetcode-cn.com/problems/solve-the-equation) | 求解方程 |  | `数学`,`字符串`,`模拟` | 中等 |  |  |
| [0641](https://leetcode-cn.com/problems/design-circular-deque) | 设计循环双端队列 |  | `设计`,`队列`,`数组`,`链表` | 中等 |  |  |
| [0642](https://leetcode-cn.com/problems/design-search-autocomplete-system) | 设计搜索自动补全系统 |  | `设计`,`字典树`,`字符串`,`数据流` | 困难 | 🔒 |  |
| [0643](https://leetcode-cn.com/problems/maximum-average-subarray-i) | 子数组最大平均数 I |  | `数组`,`滑动窗口` | 简单 |  |  |
| [0644](https://leetcode-cn.com/problems/maximum-average-subarray-ii) | 子数组最大平均数 II |  | `数组`,`二分查找` | 困难 | 🔒 |  |
| [0645](https://leetcode-cn.com/problems/set-mismatch) | 错误的集合 |  | `位运算`,`数组`,`哈希表`,`排序` | 简单 |  | ✅ |
| [0646](https://leetcode-cn.com/problems/maximum-length-of-pair-chain) | 最长数对链 |  | `贪心`,`数组`,`动态规划`,`排序` | 中等 |  |  |
| [0647](https://leetcode-cn.com/problems/palindromic-substrings) | 回文子串 |  | `字符串`,`动态规划` | 中等 |  |  |
| [0648](https://leetcode-cn.com/problems/replace-words) | 单词替换 |  | `字典树`,`数组`,`哈希表`,`字符串` | 中等 |  |  |
| [0649](https://leetcode-cn.com/problems/dota2-senate) | Dota2 参议院 |  | `贪心`,`队列`,`字符串` | 中等 |  |  |
| [0650](https://leetcode-cn.com/problems/2-keys-keyboard) | 只有两个键的键盘 |  | `数学`,`动态规划` | 中等 |  |  |
| [0651](https://leetcode-cn.com/problems/4-keys-keyboard) | 4键键盘 |  | `数学`,`动态规划` | 中等 | 🔒 |  |
| [0652](https://leetcode-cn.com/problems/find-duplicate-subtrees) | 寻找重复的子树 |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉树` | 中等 |  |  |
| [0653](https://leetcode-cn.com/problems/two-sum-iv-input-is-a-bst) | 两数之和 IV - 输入 BST |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉搜索树`,`哈希表`,`双指针`,`二叉树` | 简单 |  |  |
| [0654](https://leetcode-cn.com/problems/maximum-binary-tree) | 最大二叉树 |  | `栈`,`树`,`数组`,`分治`,`二叉树`,`单调栈` | 中等 |  |  |
| [0655](https://leetcode-cn.com/problems/print-binary-tree) | 输出二叉树 |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉树` | 中等 |  |  |
| [0656](https://leetcode-cn.com/problems/coin-path) | 金币路径 |  | `数组`,`动态规划` | 困难 | 🔒 |  |
| [0657](https://leetcode-cn.com/problems/robot-return-to-origin) | 机器人能否返回原点 |  | `字符串`,`模拟` | 简单 |  |  |
| [0658](https://leetcode-cn.com/problems/find-k-closest-elements) | 找到 K 个最接近的元素 |  | `数组`,`双指针`,`二分查找`,`排序`,`堆（优先队列）` | 中等 |  |  |
| [0659](https://leetcode-cn.com/problems/split-array-into-consecutive-subsequences) | 分割数组为连续子序列 |  | `贪心`,`数组`,`哈希表`,`堆（优先队列）` | 中等 |  |  |
| [0660](https://leetcode-cn.com/problems/remove-9) | 移除 9 |  | `数学` | 困难 | 🔒 |  |
| [0661](https://leetcode-cn.com/problems/image-smoother) | 图片平滑器 |  | `数组`,`矩阵` | 简单 |  |  |
| [0662](https://leetcode-cn.com/problems/maximum-width-of-binary-tree) | 二叉树最大宽度 |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉树` | 中等 |  |  |
| [0663](https://leetcode-cn.com/problems/equal-tree-partition) | 均匀树划分 |  | `树`,`深度优先搜索`,`二叉树` | 中等 | 🔒 |  |
| [0664](https://leetcode-cn.com/problems/strange-printer) | 奇怪的打印机 |  | `字符串`,`动态规划` | 困难 |  |  |
| [0665](https://leetcode-cn.com/problems/non-decreasing-array) | 非递减数列 |  | `数组` | 中等 |  |  |
| [0666](https://leetcode-cn.com/problems/path-sum-iv) | 路径总和 IV |  | `树`,`深度优先搜索`,`数组`,`二叉树` | 中等 | 🔒 |  |
| [0667](https://leetcode-cn.com/problems/beautiful-arrangement-ii) | 优美的排列 II |  | `数组`,`数学` | 中等 |  |  |
| [0668](https://leetcode-cn.com/problems/kth-smallest-number-in-multiplication-table) | 乘法表中第k小的数 |  | `二分查找` | 困难 |  |  |
| [0669](https://leetcode-cn.com/problems/trim-a-binary-search-tree) | 修剪二叉搜索树 |  | `树`,`深度优先搜索`,`二叉搜索树`,`二叉树` | 中等 |  |  |
| [0670](https://leetcode-cn.com/problems/maximum-swap) | 最大交换 |  | `贪心`,`数学` | 中等 |  |  |
| [0671](https://leetcode-cn.com/problems/second-minimum-node-in-a-binary-tree) | 二叉树中第二小的节点 |  | `树`,`深度优先搜索`,`二叉树` | 简单 |  |  |
| [0672](https://leetcode-cn.com/problems/bulb-switcher-ii) | 灯泡开关 Ⅱ |  | `位运算`,`深度优先搜索`,`广度优先搜索`,`数学` | 中等 |  |  |
| [0673](https://leetcode-cn.com/problems/number-of-longest-increasing-subsequence) | 最长递增子序列的个数 |  | `树状数组`,`线段树`,`数组`,`动态规划` | 中等 |  |  |
| [0674](https://leetcode-cn.com/problems/longest-continuous-increasing-subsequence) | 最长连续递增序列 |  | `数组` | 简单 |  |  |
| [0675](https://leetcode-cn.com/problems/cut-off-trees-for-golf-event) | 为高尔夫比赛砍树 |  | `广度优先搜索`,`数组`,`矩阵`,`堆（优先队列）` | 困难 |  |  |
| [0676](https://leetcode-cn.com/problems/implement-magic-dictionary) | 实现一个魔法字典 |  | `设计`,`字典树`,`哈希表`,`字符串` | 中等 |  |  |
| [0677](https://leetcode-cn.com/problems/map-sum-pairs) | 键值映射 |  | `设计`,`字典树`,`哈希表`,`字符串` | 中等 |  |  |
| [0678](https://leetcode-cn.com/problems/valid-parenthesis-string) | 有效的括号字符串 |  | `栈`,`贪心`,`字符串`,`动态规划` | 中等 |  |  |
| [0679](https://leetcode-cn.com/problems/24-game) | 24 点游戏 |  | `数组`,`数学`,`回溯` | 困难 |  |  |
| [0680](https://leetcode-cn.com/problems/valid-palindrome-ii) | 验证回文字符串 Ⅱ |  | `贪心`,`双指针`,`字符串` | 简单 |  |  |
| [0681](https://leetcode-cn.com/problems/next-closest-time) | 最近时刻 |  | `字符串`,`枚举` | 中等 | 🔒 |  |
| [0682](https://leetcode-cn.com/problems/baseball-game) | 棒球比赛 |  | `栈`,`数组`,`模拟` | 简单 |  |  |
| [0683](https://leetcode-cn.com/problems/k-empty-slots) | K 个关闭的灯泡 |  | `树状数组`,`数组`,`有序集合`,`滑动窗口` | 困难 | 🔒 |  |
| [0684](https://leetcode-cn.com/problems/redundant-connection) | 冗余连接 |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`图` | 中等 |  |  |
| [0685](https://leetcode-cn.com/problems/redundant-connection-ii) | 冗余连接 II |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`图` | 困难 |  |  |
| [0686](https://leetcode-cn.com/problems/repeated-string-match) | 重复叠加字符串匹配 |  | `字符串`,`字符串匹配` | 中等 |  |  |
| [0687](https://leetcode-cn.com/problems/longest-univalue-path) | 最长同值路径 |  | `树`,`深度优先搜索`,`二叉树` | 中等 |  |  |
| [0688](https://leetcode-cn.com/problems/knight-probability-in-chessboard) | "马"在棋盘上的概率 |  | `动态规划` | 中等 |  |  |
| [0689](https://leetcode-cn.com/problems/maximum-sum-of-3-non-overlapping-subarrays) | 三个无重叠子数组的最大和 |  | `数组`,`动态规划` | 困难 |  |  |
| [0690](https://leetcode-cn.com/problems/employee-importance) | 员工的重要性 |  | `深度优先搜索`,`广度优先搜索`,`哈希表` | 简单 |  |  |
| [0691](https://leetcode-cn.com/problems/stickers-to-spell-word) | 贴纸拼词 |  | `位运算`,`动态规划`,`回溯`,`状态压缩` | 困难 |  |  |
| [0692](https://leetcode-cn.com/problems/top-k-frequent-words) | 前K个高频单词 |  | `字典树`,`哈希表`,`字符串`,`桶排序`,`计数`,`排序`,`堆（优先队列）` | 中等 |  |  |
| [0693](https://leetcode-cn.com/problems/binary-number-with-alternating-bits) | 交替位二进制数 |  | `位运算` | 简单 |  |  |
| [0694](https://leetcode-cn.com/problems/number-of-distinct-islands) | 不同岛屿的数量 |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`哈希表`,`哈希函数` | 中等 | 🔒 |  |
| [0695](https://leetcode-cn.com/problems/max-area-of-island) | 岛屿的最大面积 |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`数组`,`矩阵` | 中等 |  |  |
| [0696](https://leetcode-cn.com/problems/count-binary-substrings) | 计数二进制子串 |  | `双指针`,`字符串` | 简单 |  |  |
| [0697](https://leetcode-cn.com/problems/degree-of-an-array) | 数组的度 |  | `数组`,`哈希表` | 简单 |  |  |
| [0698](https://leetcode-cn.com/problems/partition-to-k-equal-sum-subsets) | 划分为k个相等的子集 |  | `位运算`,`记忆化搜索`,`数组`,`动态规划`,`回溯`,`状态压缩` | 中等 |  |  |
| [0699](https://leetcode-cn.com/problems/falling-squares) | 掉落的方块 |  | `线段树`,`数组`,`有序集合` | 困难 |  |  |
| [0700](https://leetcode-cn.com/problems/search-in-a-binary-search-tree) | 二叉搜索树中的搜索 |  | `树`,`二叉搜索树`,`二叉树` | 简单 |  |  |
| [0701](https://leetcode-cn.com/problems/insert-into-a-binary-search-tree) | 二叉搜索树中的插入操作 |  | `树`,`二叉搜索树`,`二叉树` | 中等 |  |  |
| [0702](https://leetcode-cn.com/problems/search-in-a-sorted-array-of-unknown-size) | 搜索长度未知的有序数组 |  | `数组`,`二分查找`,`交互` | 中等 | 🔒 |  |
| [0703](https://leetcode-cn.com/problems/kth-largest-element-in-a-stream) | 数据流中的第 K 大元素 |  | `树`,`设计`,`二叉搜索树`,`二叉树`,`数据流`,`堆（优先队列）` | 简单 |  |  |
| [0704](https://leetcode-cn.com/problems/binary-search) | 二分查找 |  | `数组`,`二分查找` | 简单 |  |  |
| [0705](https://leetcode-cn.com/problems/design-hashset) | 设计哈希集合 |  | `设计`,`数组`,`哈希表`,`链表`,`哈希函数` | 简单 |  |  |
| [0706](https://leetcode-cn.com/problems/design-hashmap) | 设计哈希映射 |  | `设计`,`数组`,`哈希表`,`链表`,`哈希函数` | 简单 |  |  |
| [0707](https://leetcode-cn.com/problems/design-linked-list) | 设计链表 |  | `设计`,`链表` | 中等 |  |  |
| [0708](https://leetcode-cn.com/problems/insert-into-a-sorted-circular-linked-list) | 循环有序列表的插入 |  | `链表` | 中等 | 🔒 |  |
| [0709](https://leetcode-cn.com/problems/to-lower-case) | 转换成小写字母 |  | `字符串` | 简单 |  |  |
| [0710](https://leetcode-cn.com/problems/random-pick-with-blacklist) | 黑名单中的随机数 |  | `哈希表`,`数学`,`二分查找`,`排序`,`随机化` | 困难 |  |  |
| [0711](https://leetcode-cn.com/problems/number-of-distinct-islands-ii) | 不同岛屿的数量 II |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`哈希表`,`哈希函数` | 困难 | 🔒 |  |
| [0712](https://leetcode-cn.com/problems/minimum-ascii-delete-sum-for-two-strings) | 两个字符串的最小ASCII删除和 |  | `字符串`,`动态规划` | 中等 |  |  |
| [0713](https://leetcode-cn.com/problems/subarray-product-less-than-k) | 乘积小于K的子数组 |  | `数组`,`滑动窗口` | 中等 |  |  |
| [0714](https://leetcode-cn.com/problems/best-time-to-buy-and-sell-stock-with-transaction-fee) | 买卖股票的最佳时机含手续费 |  | `贪心`,`数组`,`动态规划` | 中等 |  |  |
| [0715](https://leetcode-cn.com/problems/range-module) | Range 模块 |  | `设计`,`线段树`,`有序集合` | 困难 |  |  |
| [0716](https://leetcode-cn.com/problems/max-stack) | 最大栈 |  | `栈`,`设计`,`链表`,`双向链表`,`有序集合` | 简单 | 🔒 |  |
| [0717](https://leetcode-cn.com/problems/1-bit-and-2-bit-characters) | 1比特与2比特字符 |  | `数组` | 简单 |  |  |
| [0718](https://leetcode-cn.com/problems/maximum-length-of-repeated-subarray) | 最长重复子数组 |  | `数组`,`二分查找`,`动态规划`,`滑动窗口`,`哈希函数`,`滚动哈希` | 中等 |  |  |
| [0719](https://leetcode-cn.com/problems/find-k-th-smallest-pair-distance) | 找出第 k 小的距离对 |  | `数组`,`双指针`,`二分查找`,`排序` | 困难 |  |  |
| [0720](https://leetcode-cn.com/problems/longest-word-in-dictionary) | 词典中最长的单词 |  | `字典树`,`数组`,`哈希表`,`字符串`,`排序` | 简单 |  |  |
| [0721](https://leetcode-cn.com/problems/accounts-merge) | 账户合并 |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`数组`,`字符串` | 中等 |  |  |
| [0722](https://leetcode-cn.com/problems/remove-comments) | 删除注释 |  | `数组`,`字符串` | 中等 |  |  |
| [0723](https://leetcode-cn.com/problems/candy-crush) | 粉碎糖果 |  | `数组`,`双指针`,`矩阵`,`模拟` | 中等 | 🔒 |  |
| [0724](https://leetcode-cn.com/problems/find-pivot-index) | 寻找数组的中心下标 |  | `数组`,`前缀和` | 简单 |  |  |
| [0725](https://leetcode-cn.com/problems/split-linked-list-in-parts) | 分隔链表 |  | `链表` | 中等 |  |  |
| [0726](https://leetcode-cn.com/problems/number-of-atoms) | 原子的数量 |  | `栈`,`哈希表`,`字符串` | 困难 |  |  |
| [0727](https://leetcode-cn.com/problems/minimum-window-subsequence) | 最小窗口子序列 |  | `字符串`,`动态规划`,`滑动窗口` | 困难 | 🔒 |  |
| [0728](https://leetcode-cn.com/problems/self-dividing-numbers) | 自除数 |  | `数学` | 简单 |  | ✅ |
| [0729](https://leetcode-cn.com/problems/my-calendar-i) | 我的日程安排表 I |  | `设计`,`线段树`,`有序集合` | 中等 |  |  |
| [0730](https://leetcode-cn.com/problems/count-different-palindromic-subsequences) | 统计不同回文子序列 |  | `字符串`,`动态规划` | 困难 |  |  |
| [0731](https://leetcode-cn.com/problems/my-calendar-ii) | 我的日程安排表 II |  | `设计`,`线段树`,`有序集合` | 中等 |  |  |
| [0732](https://leetcode-cn.com/problems/my-calendar-iii) | 我的日程安排表 III |  | `设计`,`线段树`,`有序集合` | 困难 |  |  |
| [0733](https://leetcode-cn.com/problems/flood-fill) | 图像渲染 |  | `深度优先搜索`,`广度优先搜索`,`数组`,`矩阵` | 简单 |  |  |
| [0734](https://leetcode-cn.com/problems/sentence-similarity) | 句子相似性 |  | `数组`,`哈希表`,`字符串` | 简单 | 🔒 |  |
| [0735](https://leetcode-cn.com/problems/asteroid-collision) | 行星碰撞 |  | `栈`,`数组` | 中等 |  |  |
| [0736](https://leetcode-cn.com/problems/parse-lisp-expression) | Lisp 语法解析 |  | `栈`,`递归`,`哈希表`,`字符串` | 困难 |  |  |
| [0737](https://leetcode-cn.com/problems/sentence-similarity-ii) | 句子相似性 II |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`数组`,`哈希表`,`字符串` | 中等 | 🔒 |  |
| [0738](https://leetcode-cn.com/problems/monotone-increasing-digits) | 单调递增的数字 |  | `贪心`,`数学` | 中等 |  |  |
| [0739](https://leetcode-cn.com/problems/daily-temperatures) | 每日温度 |  | `栈`,`数组`,`单调栈` | 中等 |  |  |
| [0740](https://leetcode-cn.com/problems/delete-and-earn) | 删除并获得点数 |  | `数组`,`哈希表`,`动态规划` | 中等 |  |  |
| [0741](https://leetcode-cn.com/problems/cherry-pickup) | 摘樱桃 |  | `数组`,`动态规划`,`矩阵` | 困难 |  |  |
| [0742](https://leetcode-cn.com/problems/closest-leaf-in-a-binary-tree) | 二叉树最近的叶节点 |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉树` | 中等 | 🔒 |  |
| [0743](https://leetcode-cn.com/problems/network-delay-time) | 网络延迟时间 |  | `深度优先搜索`,`广度优先搜索`,`图`,`最短路`,`堆（优先队列）` | 中等 |  |  |
| [0744](https://leetcode-cn.com/problems/find-smallest-letter-greater-than-target) | 寻找比目标字母大的最小字母 |  | `数组`,`二分查找` | 简单 |  |  |
| [0745](https://leetcode-cn.com/problems/prefix-and-suffix-search) | 前缀和后缀搜索 |  | `设计`,`字典树`,`字符串` | 困难 |  |  |
| [0746](https://leetcode-cn.com/problems/min-cost-climbing-stairs) | 使用最小花费爬楼梯 |  | `数组`,`动态规划` | 简单 |  |  |
| [0747](https://leetcode-cn.com/problems/largest-number-at-least-twice-of-others) | 至少是其他数字两倍的最大数 |  | `数组`,`排序` | 简单 |  |  |
| [0748](https://leetcode-cn.com/problems/shortest-completing-word) | 最短补全词 |  | `哈希表`,`字符串` | 简单 |  |  |
| [0749](https://leetcode-cn.com/problems/contain-virus) | 隔离病毒 |  | `深度优先搜索`,`广度优先搜索`,`数组`,`矩阵`,`模拟` | 困难 |  |  |
| [0750](https://leetcode-cn.com/problems/number-of-corner-rectangles) | 角矩形的数量 |  | `数组`,`数学`,`动态规划`,`矩阵` | 中等 | 🔒 |  |
| [0751](https://leetcode-cn.com/problems/ip-to-cidr) | IP 到 CIDR |  | `位运算`,`字符串` | 中等 | 🔒 |  |
| [0752](https://leetcode-cn.com/problems/open-the-lock) | 打开转盘锁 |  | `广度优先搜索`,`数组`,`哈希表`,`字符串` | 中等 |  |  |
| [0753](https://leetcode-cn.com/problems/cracking-the-safe) | 破解保险箱 |  | `深度优先搜索`,`图`,`欧拉回路` | 困难 |  |  |
| [0754](https://leetcode-cn.com/problems/reach-a-number) | 到达终点数字 |  | `数学`,`二分查找` | 中等 |  |  |
| [0755](https://leetcode-cn.com/problems/pour-water) | 倒水 |  | `数组`,`模拟` | 中等 | 🔒 |  |
| [0756](https://leetcode-cn.com/problems/pyramid-transition-matrix) | 金字塔转换矩阵 |  | `位运算`,`深度优先搜索`,`广度优先搜索` | 中等 |  |  |
| [0757](https://leetcode-cn.com/problems/set-intersection-size-at-least-two) | 设置交集大小至少为2 |  | `贪心`,`数组`,`排序` | 困难 |  |  |
| [0758](https://leetcode-cn.com/problems/bold-words-in-string) | 字符串中的加粗单词 |  | `字典树`,`数组`,`哈希表`,`字符串`,`字符串匹配` | 中等 | 🔒 |  |
| [0759](https://leetcode-cn.com/problems/employee-free-time) | 员工空闲时间 |  | `数组`,`排序`,`堆（优先队列）` | 困难 | 🔒 |  |
| [0760](https://leetcode-cn.com/problems/find-anagram-mappings) | 找出变位映射 |  | `数组`,`哈希表` | 简单 | 🔒 |  |
| [0761](https://leetcode-cn.com/problems/special-binary-string) | 特殊的二进制序列 |  | `递归`,`字符串` | 困难 |  |  |
| [0762](https://leetcode-cn.com/problems/prime-number-of-set-bits-in-binary-representation) | 二进制表示中质数个计算置位 |  | `位运算`,`数学` | 简单 |  |  |
| [0763](https://leetcode-cn.com/problems/partition-labels) | 划分字母区间 |  | `贪心`,`哈希表`,`双指针`,`字符串` | 中等 |  |  |
| [0764](https://leetcode-cn.com/problems/largest-plus-sign) | 最大加号标志 |  | `数组`,`动态规划` | 中等 |  |  |
| [0765](https://leetcode-cn.com/problems/couples-holding-hands) | 情侣牵手 |  | `贪心`,`深度优先搜索`,`广度优先搜索`,`并查集`,`图` | 困难 |  |  |
| [0766](https://leetcode-cn.com/problems/toeplitz-matrix) | 托普利茨矩阵 |  | `数组`,`矩阵` | 简单 |  |  |
| [0767](https://leetcode-cn.com/problems/reorganize-string) | 重构字符串 |  | `贪心`,`哈希表`,`字符串`,`计数`,`排序`,`堆（优先队列）` | 中等 |  |  |
| [0768](https://leetcode-cn.com/problems/max-chunks-to-make-sorted-ii) | 最多能完成排序的块 II |  | `栈`,`贪心`,`数组`,`排序`,`单调栈` | 困难 |  |  |
| [0769](https://leetcode-cn.com/problems/max-chunks-to-make-sorted) | 最多能完成排序的块 |  | `栈`,`贪心`,`数组`,`排序`,`单调栈` | 中等 |  |  |
| [0770](https://leetcode-cn.com/problems/basic-calculator-iv) | 基本计算器 IV |  | `栈`,`递归`,`哈希表`,`数学`,`字符串` | 困难 |  |  |
| [0771](https://leetcode-cn.com/problems/jewels-and-stones) | 宝石与石头 |  | `哈希表`,`字符串` | 简单 |  |  |
| [0772](https://leetcode-cn.com/problems/basic-calculator-iii) | 基本计算器 III |  | `栈`,`递归`,`数学`,`字符串` | 困难 | 🔒 |  |
| [0773](https://leetcode-cn.com/problems/sliding-puzzle) | 滑动谜题 |  | `广度优先搜索`,`数组`,`矩阵` | 困难 |  |  |
| [0774](https://leetcode-cn.com/problems/minimize-max-distance-to-gas-station) | 最小化去加油站的最大距离 |  | `数组`,`二分查找` | 困难 | 🔒 |  |
| [0775](https://leetcode-cn.com/problems/global-and-local-inversions) | 全局倒置与局部倒置 |  | `数组`,`数学` | 中等 |  |  |
| [0776](https://leetcode-cn.com/problems/split-bst) | 拆分二叉搜索树 |  | `树`,`二叉搜索树`,`递归`,`二叉树` | 中等 | 🔒 |  |
| [0777](https://leetcode-cn.com/problems/swap-adjacent-in-lr-string) | 在LR字符串中交换相邻字符 |  | `双指针`,`字符串` | 中等 |  |  |
| [0778](https://leetcode-cn.com/problems/swim-in-rising-water) | 水位上升的泳池中游泳 |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`数组`,`二分查找`,`矩阵`,`堆（优先队列）` | 困难 |  |  |
| [0779](https://leetcode-cn.com/problems/k-th-symbol-in-grammar) | 第K个语法符号 |  | `位运算`,`递归`,`数学` | 中等 |  |  |
| [0780](https://leetcode-cn.com/problems/reaching-points) | 到达终点 |  | `数学` | 困难 |  |  |
| [0781](https://leetcode-cn.com/problems/rabbits-in-forest) | 森林中的兔子 |  | `贪心`,`哈希表`,`数学` | 中等 |  |  |
| [0782](https://leetcode-cn.com/problems/transform-to-chessboard) | 变为棋盘 |  | `位运算`,`数组`,`数学`,`矩阵` | 困难 |  |  |
| [0783](https://leetcode-cn.com/problems/minimum-distance-between-bst-nodes) | 二叉搜索树节点最小距离 |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉搜索树`,`二叉树` | 简单 |  |  |
| [0784](https://leetcode-cn.com/problems/letter-case-permutation) | 字母大小写全排列 |  | `位运算`,`字符串`,`回溯` | 中等 |  |  |
| [0785](https://leetcode-cn.com/problems/is-graph-bipartite) | 判断二分图 |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`图` | 中等 |  |  |
| [0786](https://leetcode-cn.com/problems/k-th-smallest-prime-fraction) | 第 K 个最小的素数分数 |  | `数组`,`二分查找`,`堆（优先队列）` | 困难 |  |  |
| [0787](https://leetcode-cn.com/problems/cheapest-flights-within-k-stops) | K 站中转内最便宜的航班 |  | `深度优先搜索`,`广度优先搜索`,`图`,`动态规划`,`最短路`,`堆（优先队列）` | 中等 |  |  |
| [0788](https://leetcode-cn.com/problems/rotated-digits) | 旋转数字 |  | `数学`,`动态规划` | 中等 |  |  |
| [0789](https://leetcode-cn.com/problems/escape-the-ghosts) | 逃脱阻碍者 |  | `数组`,`数学` | 中等 |  |  |
| [0790](https://leetcode-cn.com/problems/domino-and-tromino-tiling) | 多米诺和托米诺平铺 |  | `动态规划` | 中等 |  |  |
| [0791](https://leetcode-cn.com/problems/custom-sort-string) | 自定义字符串排序 |  | `哈希表`,`字符串`,`排序` | 中等 |  |  |
| [0792](https://leetcode-cn.com/problems/number-of-matching-subsequences) | 匹配子序列的单词数 |  | `字典树`,`哈希表`,`字符串`,`排序` | 中等 |  |  |
| [0793](https://leetcode-cn.com/problems/preimage-size-of-factorial-zeroes-function) | 阶乘函数后 K 个零 |  | `数学`,`二分查找` | 困难 |  |  |
| [0794](https://leetcode-cn.com/problems/valid-tic-tac-toe-state) | 有效的井字游戏 |  | `数组`,`字符串` | 中等 |  |  |
| [0795](https://leetcode-cn.com/problems/number-of-subarrays-with-bounded-maximum) | 区间子数组个数 |  | `数组`,`双指针` | 中等 |  |  |
| [0796](https://leetcode-cn.com/problems/rotate-string) | 旋转字符串 |  | `字符串`,`字符串匹配` | 简单 |  |  |
| [0797](https://leetcode-cn.com/problems/all-paths-from-source-to-target) | 所有可能的路径 |  | `深度优先搜索`,`广度优先搜索`,`图`,`回溯` | 中等 |  |  |
| [0798](https://leetcode-cn.com/problems/smallest-rotation-with-highest-score) | 得分最高的最小轮调 |  | `数组`,`前缀和` | 困难 |  |  |
| [0799](https://leetcode-cn.com/problems/champagne-tower) | 香槟塔 |  | `动态规划` | 中等 |  |  |
| [0800](https://leetcode-cn.com/problems/similar-rgb-color) | 相似 RGB 颜色 |  | `数学`,`字符串`,`枚举` | 简单 | 🔒 |  |
| [0801](https://leetcode-cn.com/problems/minimum-swaps-to-make-sequences-increasing) | 使序列递增的最小交换次数 |  | `数组`,`动态规划` | 困难 |  |  |
| [0802](https://leetcode-cn.com/problems/find-eventual-safe-states) | 找到最终的安全状态 |  | `深度优先搜索`,`广度优先搜索`,`图`,`拓扑排序` | 中等 |  |  |
| [0803](https://leetcode-cn.com/problems/bricks-falling-when-hit) | 打砖块 |  | `并查集`,`数组`,`矩阵` | 困难 |  |  |
| [0804](https://leetcode-cn.com/problems/unique-morse-code-words) | 唯一摩尔斯密码词 |  | `数组`,`哈希表`,`字符串` | 简单 |  |  |
| [0805](https://leetcode-cn.com/problems/split-array-with-same-average) | 数组的均值分割 |  | `位运算`,`数组`,`数学`,`动态规划`,`状态压缩` | 困难 |  |  |
| [0806](https://leetcode-cn.com/problems/number-of-lines-to-write-string) | 写字符串需要的行数 |  | `数组`,`字符串` | 简单 |  |  |
| [0807](https://leetcode-cn.com/problems/max-increase-to-keep-city-skyline) | 保持城市天际线 |  | `贪心`,`数组`,`矩阵` | 中等 |  |  |
| [0808](https://leetcode-cn.com/problems/soup-servings) | 分汤 |  | `数学`,`动态规划`,`概率与统计` | 中等 |  |  |
| [0809](https://leetcode-cn.com/problems/expressive-words) | 情感丰富的文字 |  | `数组`,`双指针`,`字符串` | 中等 |  |  |
| [0810](https://leetcode-cn.com/problems/chalkboard-xor-game) | 黑板异或游戏 |  | `位运算`,`脑筋急转弯`,`数组`,`数学`,`博弈` | 困难 |  |  |
| [0811](https://leetcode-cn.com/problems/subdomain-visit-count) | 子域名访问计数 |  | `数组`,`哈希表`,`字符串` | 简单 |  |  |
| [0812](https://leetcode-cn.com/problems/largest-triangle-area) | 最大三角形面积 |  | `几何`,`数组`,`数学` | 简单 |  |  |
| [0813](https://leetcode-cn.com/problems/largest-sum-of-averages) | 最大平均值和的分组 |  | `数组`,`动态规划` | 中等 |  |  |
| [0814](https://leetcode-cn.com/problems/binary-tree-pruning) | 二叉树剪枝 |  | `树`,`深度优先搜索`,`二叉树` | 中等 |  |  |
| [0815](https://leetcode-cn.com/problems/bus-routes) | 公交路线 |  | `广度优先搜索`,`数组`,`哈希表` | 困难 |  |  |
| [0816](https://leetcode-cn.com/problems/ambiguous-coordinates) | 模糊坐标 |  | `字符串`,`回溯` | 中等 |  |  |
| [0817](https://leetcode-cn.com/problems/linked-list-components) | 链表组件 |  | `哈希表`,`链表` | 中等 |  |  |
| [0818](https://leetcode-cn.com/problems/race-car) | 赛车 |  | `动态规划` | 困难 |  |  |
| [0819](https://leetcode-cn.com/problems/most-common-word) | 最常见的单词 |  | `哈希表`,`字符串` | 简单 |  |  |
| [0820](https://leetcode-cn.com/problems/short-encoding-of-words) | 单词的压缩编码 |  | `字典树`,`数组`,`哈希表`,`字符串` | 中等 |  |  |
| [0821](https://leetcode-cn.com/problems/shortest-distance-to-a-character) | 字符的最短距离 |  | `数组`,`双指针`,`字符串` | 简单 |  |  |
| [0822](https://leetcode-cn.com/problems/card-flipping-game) | 翻转卡片游戏 |  | `数组`,`哈希表` | 中等 |  |  |
| [0823](https://leetcode-cn.com/problems/binary-trees-with-factors) | 带因子的二叉树 |  | `数组`,`哈希表`,`动态规划` | 中等 |  |  |
| [0824](https://leetcode-cn.com/problems/goat-latin) | 山羊拉丁文 |  | `字符串` | 简单 |  |  |
| [0825](https://leetcode-cn.com/problems/friends-of-appropriate-ages) | 适龄的朋友 |  | `数组`,`双指针`,`二分查找`,`排序` | 中等 |  |  |
| [0826](https://leetcode-cn.com/problems/most-profit-assigning-work) | 安排工作以达到最大收益 |  | `贪心`,`数组`,`双指针`,`二分查找`,`排序` | 中等 |  |  |
| [0827](https://leetcode-cn.com/problems/making-a-large-island) | 最大人工岛 |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`数组`,`矩阵` | 困难 |  |  |
| [0828](https://leetcode-cn.com/problems/count-unique-characters-of-all-substrings-of-a-given-string) | 统计子串中的唯一字符 |  | `字符串`,`动态规划` | 困难 |  |  |
| [0829](https://leetcode-cn.com/problems/consecutive-numbers-sum) | 连续整数求和 |  | `数学`,`枚举` | 困难 |  |  |
| [0830](https://leetcode-cn.com/problems/positions-of-large-groups) | 较大分组的位置 |  | `字符串` | 简单 |  |  |
| [0831](https://leetcode-cn.com/problems/masking-personal-information) | 隐藏个人信息 |  | `字符串` | 中等 |  |  |
| [0832](https://leetcode-cn.com/problems/flipping-an-image) | 翻转图像 |  | `数组`,`双指针`,`矩阵`,`模拟` | 简单 |  |  |
| [0833](https://leetcode-cn.com/problems/find-and-replace-in-string) | 字符串中的查找与替换 |  | `数组`,`字符串`,`排序` | 中等 |  |  |
| [0834](https://leetcode-cn.com/problems/sum-of-distances-in-tree) | 树中距离之和 |  | `树`,`深度优先搜索`,`图`,`动态规划` | 困难 |  |  |
| [0835](https://leetcode-cn.com/problems/image-overlap) | 图像重叠 |  | `数组`,`矩阵` | 中等 |  |  |
| [0836](https://leetcode-cn.com/problems/rectangle-overlap) | 矩形重叠 |  | `几何`,`数学` | 简单 |  |  |
| [0837](https://leetcode-cn.com/problems/new-21-game) | 新21点 |  | `数学`,`动态规划`,`滑动窗口`,`概率与统计` | 中等 |  |  |
| [0838](https://leetcode-cn.com/problems/push-dominoes) | 推多米诺 |  | `双指针`,`字符串`,`动态规划` | 中等 |  |  |
| [0839](https://leetcode-cn.com/problems/similar-string-groups) | 相似字符串组 |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`字符串` | 困难 |  |  |
| [0840](https://leetcode-cn.com/problems/magic-squares-in-grid) | 矩阵中的幻方 |  | `数组`,`数学`,`矩阵` | 中等 |  |  |
| [0841](https://leetcode-cn.com/problems/keys-and-rooms) | 钥匙和房间 |  | `深度优先搜索`,`广度优先搜索`,`图` | 中等 |  |  |
| [0842](https://leetcode-cn.com/problems/split-array-into-fibonacci-sequence) | 将数组拆分成斐波那契序列 |  | `字符串`,`回溯` | 中等 |  |  |
| [0843](https://leetcode-cn.com/problems/guess-the-word) | 猜猜这个单词 |  | `数组`,`数学`,`字符串`,`博弈`,`交互` | 困难 |  |  |
| [0844](https://leetcode-cn.com/problems/backspace-string-compare) | 比较含退格的字符串 |  | `栈`,`双指针`,`字符串`,`模拟` | 简单 |  |  |
| [0845](https://leetcode-cn.com/problems/longest-mountain-in-array) | 数组中的最长山脉 |  | `数组`,`双指针`,`动态规划`,`枚举` | 中等 |  |  |
| [0846](https://leetcode-cn.com/problems/hand-of-straights) | 一手顺子 |  | `贪心`,`数组`,`哈希表`,`排序` | 中等 |  |  |
| [0847](https://leetcode-cn.com/problems/shortest-path-visiting-all-nodes) | 访问所有节点的最短路径 |  | `位运算`,`广度优先搜索`,`图`,`动态规划`,`状态压缩` | 困难 |  |  |
| [0848](https://leetcode-cn.com/problems/shifting-letters) | 字母移位 |  | `数组`,`字符串` | 中等 |  |  |
| [0849](https://leetcode-cn.com/problems/maximize-distance-to-closest-person) | 到最近的人的最大距离 |  | `数组` | 中等 |  |  |
| [0850](https://leetcode-cn.com/problems/rectangle-area-ii) | 矩形面积 II |  | `线段树`,`数组`,`有序集合`,`扫描线` | 困难 |  |  |
| [0851](https://leetcode-cn.com/problems/loud-and-rich) | 喧闹和富有 |  | `深度优先搜索`,`图`,`拓扑排序`,`数组` | 中等 |  |  |
| [0852](https://leetcode-cn.com/problems/peak-index-in-a-mountain-array) | 山脉数组的峰顶索引 |  | `数组`,`二分查找` | 简单 |  |  |
| [0853](https://leetcode-cn.com/problems/car-fleet) | 车队 |  | `数组`,`排序` | 中等 |  |  |
| [0854](https://leetcode-cn.com/problems/k-similar-strings) | 相似度为 K 的字符串 |  | `广度优先搜索`,`字符串` | 困难 |  |  |
| [0855](https://leetcode-cn.com/problems/exam-room) | 考场就座 |  | `设计`,`有序集合` | 中等 |  |  |
| [0856](https://leetcode-cn.com/problems/score-of-parentheses) | 括号的分数 |  | `栈`,`字符串` | 中等 |  |  |
| [0857](https://leetcode-cn.com/problems/minimum-cost-to-hire-k-workers) | 雇佣 K 名工人的最低成本 |  | `贪心`,`数组`,`排序`,`堆（优先队列）` | 困难 |  |  |
| [0858](https://leetcode-cn.com/problems/mirror-reflection) | 镜面反射 |  | `几何`,`数学` | 中等 |  |  |
| [0859](https://leetcode-cn.com/problems/buddy-strings) | 亲密字符串 |  | `哈希表`,`字符串` | 简单 |  |  |
| [0860](https://leetcode-cn.com/problems/lemonade-change) | 柠檬水找零 |  | `贪心`,`数组` | 简单 |  |  |
| [0861](https://leetcode-cn.com/problems/score-after-flipping-matrix) | 翻转矩阵后的得分 |  | `贪心`,`位运算`,`数组`,`矩阵` | 中等 |  |  |
| [0862](https://leetcode-cn.com/problems/shortest-subarray-with-sum-at-least-k) | 和至少为 K 的最短子数组 |  | `队列`,`数组`,`二分查找`,`前缀和`,`滑动窗口`,`单调队列`,`堆（优先队列）` | 困难 |  |  |
| [0863](https://leetcode-cn.com/problems/all-nodes-distance-k-in-binary-tree) | 二叉树中所有距离为 K 的结点 |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉树` | 中等 |  |  |
| [0864](https://leetcode-cn.com/problems/shortest-path-to-get-all-keys) | 获取所有钥匙的最短路径 |  | `位运算`,`广度优先搜索` | 困难 |  |  |
| [0865](https://leetcode-cn.com/problems/smallest-subtree-with-all-the-deepest-nodes) | 具有所有最深节点的最小子树 |  | `树`,`深度优先搜索`,`广度优先搜索`,`哈希表`,`二叉树` | 中等 |  |  |
| [0866](https://leetcode-cn.com/problems/prime-palindrome) | 回文素数 |  | `数学` | 中等 |  |  |
| [0867](https://leetcode-cn.com/problems/transpose-matrix) | 转置矩阵 |  | `数组`,`矩阵`,`模拟` | 简单 |  |  |
| [0868](https://leetcode-cn.com/problems/binary-gap) | 二进制间距 |  | `位运算`,`数学` | 简单 |  |  |
| [0869](https://leetcode-cn.com/problems/reordered-power-of-2) | 重新排序得到 2 的幂 |  | `数学`,`计数`,`枚举`,`排序` | 中等 |  |  |
| [0870](https://leetcode-cn.com/problems/advantage-shuffle) | 优势洗牌 |  | `贪心`,`数组`,`排序` | 中等 |  |  |
| [0871](https://leetcode-cn.com/problems/minimum-number-of-refueling-stops) | 最低加油次数 |  | `贪心`,`数组`,`动态规划`,`堆（优先队列）` | 困难 |  |  |
| [0872](https://leetcode-cn.com/problems/leaf-similar-trees) | 叶子相似的树 |  | `树`,`深度优先搜索`,`二叉树` | 简单 |  |  |
| [0873](https://leetcode-cn.com/problems/length-of-longest-fibonacci-subsequence) | 最长的斐波那契子序列的长度 |  | `数组`,`哈希表`,`动态规划` | 中等 |  |  |
| [0874](https://leetcode-cn.com/problems/walking-robot-simulation) | 模拟行走机器人 |  | `数组`,`模拟` | 简单 |  |  |
| [0875](https://leetcode-cn.com/problems/koko-eating-bananas) | 爱吃香蕉的珂珂 |  | `数组`,`二分查找` | 中等 |  |  |
| [0876](https://leetcode-cn.com/problems/middle-of-the-linked-list) | 链表的中间结点 |  | `链表`,`双指针` | 简单 |  |  |
| [0877](https://leetcode-cn.com/problems/stone-game) | 石子游戏 |  | `数组`,`数学`,`动态规划`,`博弈` | 中等 |  |  |
| [0878](https://leetcode-cn.com/problems/nth-magical-number) | 第 N 个神奇数字 |  | `数学`,`二分查找` | 困难 |  |  |
| [0879](https://leetcode-cn.com/problems/profitable-schemes) | 盈利计划 |  | `数组`,`动态规划` | 困难 |  |  |
| [0880](https://leetcode-cn.com/problems/decoded-string-at-index) | 索引处的解码字符串 |  | `栈`,`字符串` | 中等 |  |  |
| [0881](https://leetcode-cn.com/problems/boats-to-save-people) | 救生艇 |  | `贪心`,`数组`,`双指针`,`排序` | 中等 |  |  |
| [0882](https://leetcode-cn.com/problems/reachable-nodes-in-subdivided-graph) | 细分图中的可到达结点 |  | `图`,`最短路`,`堆（优先队列）` | 困难 |  |  |
| [0883](https://leetcode-cn.com/problems/projection-area-of-3d-shapes) | 三维形体投影面积 |  | `几何`,`数组`,`数学`,`矩阵` | 简单 |  |  |
| [0884](https://leetcode-cn.com/problems/uncommon-words-from-two-sentences) | 两句话中的不常见单词 |  | `哈希表`,`字符串` | 简单 |  |  |
| [0885](https://leetcode-cn.com/problems/spiral-matrix-iii) | 螺旋矩阵 III |  | `数组`,`矩阵`,`模拟` | 中等 |  |  |
| [0886](https://leetcode-cn.com/problems/possible-bipartition) | 可能的二分法 |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`图` | 中等 |  |  |
| [0887](https://leetcode-cn.com/problems/super-egg-drop) | 鸡蛋掉落 |  | `数学`,`二分查找`,`动态规划` | 困难 |  |  |
| [0888](https://leetcode-cn.com/problems/fair-candy-swap) | 公平的糖果棒交换 |  | `数组`,`哈希表`,`二分查找`,`排序` | 简单 |  |  |
| [0889](https://leetcode-cn.com/problems/construct-binary-tree-from-preorder-and-postorder-traversal) | 根据前序和后序遍历构造二叉树 |  | `树`,`数组`,`哈希表`,`分治`,`二叉树` | 中等 |  |  |
| [0890](https://leetcode-cn.com/problems/find-and-replace-pattern) | 查找和替换模式 |  | `数组`,`哈希表`,`字符串` | 中等 |  |  |
| [0891](https://leetcode-cn.com/problems/sum-of-subsequence-widths) | 子序列宽度之和 |  | `数组`,`数学`,`排序` | 困难 |  |  |
| [0892](https://leetcode-cn.com/problems/surface-area-of-3d-shapes) | 三维形体的表面积 |  | `几何`,`数组`,`数学`,`矩阵` | 简单 |  |  |
| [0893](https://leetcode-cn.com/problems/groups-of-special-equivalent-strings) | 特殊等价字符串组 |  | `数组`,`哈希表`,`字符串` | 简单 |  |  |
| [0894](https://leetcode-cn.com/problems/all-possible-full-binary-trees) | 所有可能的满二叉树 |  | `树`,`递归`,`记忆化搜索`,`动态规划`,`二叉树` | 中等 |  |  |
| [0895](https://leetcode-cn.com/problems/maximum-frequency-stack) | 最大频率栈 |  | `栈`,`设计`,`哈希表`,`有序集合` | 困难 |  |  |
| [0896](https://leetcode-cn.com/problems/monotonic-array) | 单调数列 |  | `数组` | 简单 |  |  |
| [0897](https://leetcode-cn.com/problems/increasing-order-search-tree) | 递增顺序搜索树 |  | `栈`,`树`,`深度优先搜索`,`二叉搜索树`,`二叉树` | 简单 |  |  |
| [0898](https://leetcode-cn.com/problems/bitwise-ors-of-subarrays) | 子数组按位或操作 |  | `位运算`,`数组`,`动态规划` | 中等 |  |  |
| [0899](https://leetcode-cn.com/problems/orderly-queue) | 有序队列 |  | `数学`,`字符串`,`排序` | 困难 |  |  |
| [0900](https://leetcode-cn.com/problems/rle-iterator) | RLE 迭代器 |  | `设计`,`数组`,`计数`,`迭代器` | 中等 |  |  |
| [0901](https://leetcode-cn.com/problems/online-stock-span) | 股票价格跨度 |  | `栈`,`设计`,`数据流`,`单调栈` | 中等 |  |  |
| [0902](https://leetcode-cn.com/problems/numbers-at-most-n-given-digit-set) | 最大为 N 的数字组合 |  | `数组`,`数学`,`二分查找`,`动态规划` | 困难 |  |  |
| [0903](https://leetcode-cn.com/problems/valid-permutations-for-di-sequence) | DI 序列的有效排列 |  | `动态规划` | 困难 |  |  |
| [0904](https://leetcode-cn.com/problems/fruit-into-baskets) | 水果成篮 |  | `数组`,`哈希表`,`滑动窗口` | 中等 |  |  |
| [0905](https://leetcode-cn.com/problems/sort-array-by-parity) | 按奇偶排序数组 |  | `数组`,`双指针`,`排序` | 简单 |  |  |
| [0906](https://leetcode-cn.com/problems/super-palindromes) | 超级回文数 |  | `数学`,`枚举` | 困难 |  |  |
| [0907](https://leetcode-cn.com/problems/sum-of-subarray-minimums) | 子数组的最小值之和 |  | `栈`,`数组`,`动态规划`,`单调栈` | 中等 |  |  |
| [0908](https://leetcode-cn.com/problems/smallest-range-i) | 最小差值 I |  | `数组`,`数学` | 简单 |  |  |
| [0909](https://leetcode-cn.com/problems/snakes-and-ladders) | 蛇梯棋 |  | `广度优先搜索`,`数组`,`矩阵` | 中等 |  |  |
| [0910](https://leetcode-cn.com/problems/smallest-range-ii) | 最小差值 II |  | `贪心`,`数组`,`数学`,`排序` | 中等 |  |  |
| [0911](https://leetcode-cn.com/problems/online-election) | 在线选举 |  | `设计`,`数组`,`哈希表`,`二分查找` | 中等 |  |  |
| [0912](https://leetcode-cn.com/problems/sort-an-array) | 排序数组 |  | `数组`,`分治`,`桶排序`,`计数排序`,`基数排序`,`排序`,`堆（优先队列）`,`归并排序` | 中等 |  |  |
| [0913](https://leetcode-cn.com/problems/cat-and-mouse) | 猫和老鼠 |  | `广度优先搜索`,`图`,`记忆化搜索`,`数学`,`动态规划`,`博弈` | 困难 |  |  |
| [0914](https://leetcode-cn.com/problems/x-of-a-kind-in-a-deck-of-cards) | 卡牌分组 |  | `数组`,`哈希表`,`数学`,`计数`,`数论` | 简单 |  |  |
| [0915](https://leetcode-cn.com/problems/partition-array-into-disjoint-intervals) | 分割数组 |  | `数组` | 中等 |  |  |
| [0916](https://leetcode-cn.com/problems/word-subsets) | 单词子集 |  | `数组`,`哈希表`,`字符串` | 中等 |  |  |
| [0917](https://leetcode-cn.com/problems/reverse-only-letters) | 仅仅反转字母 |  | `双指针`,`字符串` | 简单 |  |  |
| [0918](https://leetcode-cn.com/problems/maximum-sum-circular-subarray) | 环形子数组的最大和 |  | `队列`,`数组`,`分治`,`动态规划`,`单调队列` | 中等 |  |  |
| [0919](https://leetcode-cn.com/problems/complete-binary-tree-inserter) | 完全二叉树插入器 |  | `树`,`广度优先搜索`,`设计`,`二叉树` | 中等 |  |  |
| [0920](https://leetcode-cn.com/problems/number-of-music-playlists) | 播放列表的数量 |  | `数学`,`动态规划`,`组合数学` | 困难 |  |  |
| [0921](https://leetcode-cn.com/problems/minimum-add-to-make-parentheses-valid) | 使括号有效的最少添加 |  | `栈`,`贪心`,`字符串` | 中等 |  |  |
| [0922](https://leetcode-cn.com/problems/sort-array-by-parity-ii) | 按奇偶排序数组 II |  | `数组`,`双指针`,`排序` | 简单 |  |  |
| [0923](https://leetcode-cn.com/problems/3sum-with-multiplicity) | 三数之和的多种可能 |  | `数组`,`哈希表`,`双指针`,`计数`,`排序` | 中等 |  |  |
| [0924](https://leetcode-cn.com/problems/minimize-malware-spread) | 尽量减少恶意软件的传播 |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`数组`,`矩阵` | 困难 |  |  |
| [0925](https://leetcode-cn.com/problems/long-pressed-name) | 长按键入 |  | `双指针`,`字符串` | 简单 |  |  |
| [0926](https://leetcode-cn.com/problems/flip-string-to-monotone-increasing) | 将字符串翻转到单调递增 |  | `字符串`,`动态规划` | 中等 |  |  |
| [0927](https://leetcode-cn.com/problems/three-equal-parts) | 三等分 |  | `数组`,`数学` | 困难 |  |  |
| [0928](https://leetcode-cn.com/problems/minimize-malware-spread-ii) | 尽量减少恶意软件的传播 II |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`数组`,`矩阵` | 困难 |  |  |
| [0929](https://leetcode-cn.com/problems/unique-email-addresses) | 独特的电子邮件地址 |  | `数组`,`哈希表`,`字符串` | 简单 |  |  |
| [0930](https://leetcode-cn.com/problems/binary-subarrays-with-sum) | 和相同的二元子数组 |  | `数组`,`哈希表`,`前缀和`,`滑动窗口` | 中等 |  |  |
| [0931](https://leetcode-cn.com/problems/minimum-falling-path-sum) | 下降路径最小和 |  | `数组`,`动态规划`,`矩阵` | 中等 |  |  |
| [0932](https://leetcode-cn.com/problems/beautiful-array) | 漂亮数组 |  | `数组`,`数学`,`分治` | 中等 |  |  |
| [0933](https://leetcode-cn.com/problems/number-of-recent-calls) | 最近的请求次数 |  | `设计`,`队列`,`数据流` | 简单 |  |  |
| [0934](https://leetcode-cn.com/problems/shortest-bridge) | 最短的桥 |  | `深度优先搜索`,`广度优先搜索`,`数组`,`矩阵` | 中等 |  |  |
| [0935](https://leetcode-cn.com/problems/knight-dialer) | 骑士拨号器 |  | `动态规划` | 中等 |  |  |
| [0936](https://leetcode-cn.com/problems/stamping-the-sequence) | 戳印序列 |  | `栈`,`贪心`,`队列`,`字符串` | 困难 |  |  |
| [0937](https://leetcode-cn.com/problems/reorder-data-in-log-files) | 重新排列日志文件 |  | `数组`,`字符串`,`排序` | 简单 |  |  |
| [0938](https://leetcode-cn.com/problems/range-sum-of-bst) | 二叉搜索树的范围和 |  | `树`,`深度优先搜索`,`二叉搜索树`,`二叉树` | 简单 |  |  |
| [0939](https://leetcode-cn.com/problems/minimum-area-rectangle) | 最小面积矩形 |  | `几何`,`数组`,`哈希表`,`数学`,`排序` | 中等 |  |  |
| [0940](https://leetcode-cn.com/problems/distinct-subsequences-ii) | 不同的子序列 II |  | `字符串`,`动态规划` | 困难 |  |  |
| [0941](https://leetcode-cn.com/problems/valid-mountain-array) | 有效的山脉数组 |  | `数组` | 简单 |  |  |
| [0942](https://leetcode-cn.com/problems/di-string-match) | 增减字符串匹配 |  | `贪心`,`数组`,`数学`,`双指针`,`字符串` | 简单 |  |  |
| [0943](https://leetcode-cn.com/problems/find-the-shortest-superstring) | 最短超级串 |  | `位运算`,`数组`,`字符串`,`动态规划`,`状态压缩` | 困难 |  |  |
| [0944](https://leetcode-cn.com/problems/delete-columns-to-make-sorted) | 删列造序 |  | `数组`,`字符串` | 简单 |  |  |
| [0945](https://leetcode-cn.com/problems/minimum-increment-to-make-array-unique) | 使数组唯一的最小增量 |  | `贪心`,`数组`,`计数`,`排序` | 中等 |  |  |
| [0946](https://leetcode-cn.com/problems/validate-stack-sequences) | 验证栈序列 |  | `栈`,`数组`,`模拟` | 中等 |  |  |
| [0947](https://leetcode-cn.com/problems/most-stones-removed-with-same-row-or-column) | 移除最多的同行或同列石头 |  | `深度优先搜索`,`并查集`,`图` | 中等 |  |  |
| [0948](https://leetcode-cn.com/problems/bag-of-tokens) | 令牌放置 |  | `贪心`,`数组`,`双指针`,`排序` | 中等 |  |  |
| [0949](https://leetcode-cn.com/problems/largest-time-for-given-digits) | 给定数字能组成的最大时间 |  | `字符串`,`枚举` | 中等 |  |  |
| [0950](https://leetcode-cn.com/problems/reveal-cards-in-increasing-order) | 按递增顺序显示卡牌 |  | `队列`,`数组`,`排序`,`模拟` | 中等 |  |  |
| [0951](https://leetcode-cn.com/problems/flip-equivalent-binary-trees) | 翻转等价二叉树 |  | `树`,`深度优先搜索`,`二叉树` | 中等 |  |  |
| [0952](https://leetcode-cn.com/problems/largest-component-size-by-common-factor) | 按公因数计算最大组件大小 |  | `并查集`,`数组`,`数学` | 困难 |  |  |
| [0953](https://leetcode-cn.com/problems/verifying-an-alien-dictionary) | 验证外星语词典 |  | `数组`,`哈希表`,`字符串` | 简单 |  |  |
| [0954](https://leetcode-cn.com/problems/array-of-doubled-pairs) | 二倍数对数组 |  | `贪心`,`数组`,`哈希表`,`排序` | 中等 |  |  |
| [0955](https://leetcode-cn.com/problems/delete-columns-to-make-sorted-ii) | 删列造序 II |  | `贪心`,`数组`,`字符串` | 中等 |  |  |
| [0956](https://leetcode-cn.com/problems/tallest-billboard) | 最高的广告牌 |  | `数组`,`动态规划` | 困难 |  |  |
| [0957](https://leetcode-cn.com/problems/prison-cells-after-n-days) | N 天后的牢房 |  | `位运算`,`数组`,`哈希表`,`数学` | 中等 |  |  |
| [0958](https://leetcode-cn.com/problems/check-completeness-of-a-binary-tree) | 二叉树的完全性检验 |  | `树`,`广度优先搜索`,`二叉树` | 中等 |  |  |
| [0959](https://leetcode-cn.com/problems/regions-cut-by-slashes) | 由斜杠划分区域 |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`图` | 中等 |  |  |
| [0960](https://leetcode-cn.com/problems/delete-columns-to-make-sorted-iii) | 删列造序 III |  | `数组`,`字符串`,`动态规划` | 困难 |  |  |
| [0961](https://leetcode-cn.com/problems/n-repeated-element-in-size-2n-array) | 重复 N 次的元素 |  | `数组`,`哈希表` | 简单 |  |  |
| [0962](https://leetcode-cn.com/problems/maximum-width-ramp) | 最大宽度坡 |  | `栈`,`数组`,`单调栈` | 中等 |  |  |
| [0963](https://leetcode-cn.com/problems/minimum-area-rectangle-ii) | 最小面积矩形 II |  | `几何`,`数组`,`数学` | 中等 |  |  |
| [0964](https://leetcode-cn.com/problems/least-operators-to-express-number) | 表示数字的最少运算符 |  | `数学`,`动态规划` | 困难 |  |  |
| [0965](https://leetcode-cn.com/problems/univalued-binary-tree) | 单值二叉树 |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉树` | 简单 |  |  |
| [0966](https://leetcode-cn.com/problems/vowel-spellchecker) | 元音拼写检查器 |  | `数组`,`哈希表`,`字符串` | 中等 |  |  |
| [0967](https://leetcode-cn.com/problems/numbers-with-same-consecutive-differences) | 连续差相同的数字 |  | `广度优先搜索`,`回溯` | 中等 |  |  |
| [0968](https://leetcode-cn.com/problems/binary-tree-cameras) | 监控二叉树 |  | `树`,`深度优先搜索`,`动态规划`,`二叉树` | 困难 |  |  |
| [0969](https://leetcode-cn.com/problems/pancake-sorting) | 煎饼排序 |  | `贪心`,`数组`,`双指针`,`排序` | 中等 |  |  |
| [0970](https://leetcode-cn.com/problems/powerful-integers) | 强整数 |  | `哈希表`,`数学` | 中等 |  |  |
| [0971](https://leetcode-cn.com/problems/flip-binary-tree-to-match-preorder-traversal) | 翻转二叉树以匹配先序遍历 |  | `树`,`深度优先搜索`,`二叉树` | 中等 |  |  |
| [0972](https://leetcode-cn.com/problems/equal-rational-numbers) | 相等的有理数 |  | `数学`,`字符串` | 困难 |  |  |
| [0973](https://leetcode-cn.com/problems/k-closest-points-to-origin) | 最接近原点的 K 个点 |  | `几何`,`数组`,`数学`,`分治`,`快速选择`,`排序`,`堆（优先队列）` | 中等 |  |  |
| [0974](https://leetcode-cn.com/problems/subarray-sums-divisible-by-k) | 和可被 K 整除的子数组 |  | `数组`,`哈希表`,`前缀和` | 中等 |  |  |
| [0975](https://leetcode-cn.com/problems/odd-even-jump) | 奇偶跳 |  | `栈`,`数组`,`动态规划`,`有序集合`,`单调栈` | 困难 |  |  |
| [0976](https://leetcode-cn.com/problems/largest-perimeter-triangle) | 三角形的最大周长 |  | `贪心`,`数组`,`数学`,`排序` | 简单 |  | ✅ |
| [0977](https://leetcode-cn.com/problems/squares-of-a-sorted-array) | 有序数组的平方 |  | `数组`,`双指针`,`排序` | 简单 |  | ✅ |
| [0978](https://leetcode-cn.com/problems/longest-turbulent-subarray) | 最长湍流子数组 |  | `数组`,`动态规划`,`滑动窗口` | 中等 |  |  |
| [0979](https://leetcode-cn.com/problems/distribute-coins-in-binary-tree) | 在二叉树中分配硬币 |  | `树`,`深度优先搜索`,`二叉树` | 中等 |  |  |
| [0980](https://leetcode-cn.com/problems/unique-paths-iii) | 不同路径 III |  | `位运算`,`数组`,`回溯`,`矩阵` | 困难 |  |  |
| [0981](https://leetcode-cn.com/problems/time-based-key-value-store) | 基于时间的键值存储 |  | `设计`,`哈希表`,`字符串`,`二分查找` | 中等 |  |  |
| [0982](https://leetcode-cn.com/problems/triples-with-bitwise-and-equal-to-zero) | 按位与为零的三元组 |  | `位运算`,`数组`,`哈希表` | 困难 |  |  |
| [0983](https://leetcode-cn.com/problems/minimum-cost-for-tickets) | 最低票价 |  | `数组`,`动态规划` | 中等 |  |  |
| [0984](https://leetcode-cn.com/problems/string-without-aaa-or-bbb) | 不含 AAA 或 BBB 的字符串 |  | `贪心`,`字符串` | 中等 |  |  |
| [0985](https://leetcode-cn.com/problems/sum-of-even-numbers-after-queries) | 查询后的偶数和 |  | `数组`,`模拟` | 简单 |  |  |
| [0986](https://leetcode-cn.com/problems/interval-list-intersections) | 区间列表的交集 |  | `数组`,`双指针` | 中等 |  |  |
| [0987](https://leetcode-cn.com/problems/vertical-order-traversal-of-a-binary-tree) | 二叉树的垂序遍历 |  | `树`,`深度优先搜索`,`广度优先搜索`,`哈希表`,`二叉树` | 困难 |  |  |
| [0988](https://leetcode-cn.com/problems/smallest-string-starting-from-leaf) | 从叶结点开始的最小字符串 |  | `树`,`深度优先搜索`,`字符串`,`二叉树` | 中等 |  |  |
| [0989](https://leetcode-cn.com/problems/add-to-array-form-of-integer) | 数组形式的整数加法 |  | `数组`,`数学` | 简单 |  |  |
| [0990](https://leetcode-cn.com/problems/satisfiability-of-equality-equations) | 等式方程的可满足性 |  | `并查集`,`图`,`数组`,`字符串` | 中等 |  |  |
| [0991](https://leetcode-cn.com/problems/broken-calculator) | 坏了的计算器 |  | `贪心`,`数学` | 中等 |  |  |
| [0992](https://leetcode-cn.com/problems/subarrays-with-k-different-integers) | K 个不同整数的子数组 |  | `数组`,`哈希表`,`计数`,`滑动窗口` | 困难 |  |  |
| [0993](https://leetcode-cn.com/problems/cousins-in-binary-tree) | 二叉树的堂兄弟节点 |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉树` | 简单 |  |  |
| [0994](https://leetcode-cn.com/problems/rotting-oranges) | 腐烂的橘子 |  | `广度优先搜索`,`数组`,`矩阵` | 中等 |  |  |
| [0995](https://leetcode-cn.com/problems/minimum-number-of-k-consecutive-bit-flips) | K 连续位的最小翻转次数 |  | `位运算`,`数组`,`前缀和`,`滑动窗口` | 困难 |  |  |
| [0996](https://leetcode-cn.com/problems/number-of-squareful-arrays) | 正方形数组的数目 |  | `位运算`,`数组`,`数学`,`动态规划`,`回溯`,`状态压缩` | 困难 |  |  |
| [0997](https://leetcode-cn.com/problems/find-the-town-judge) | 找到小镇的法官 |  | `图`,`数组`,`哈希表` | 简单 |  |  |
| [0998](https://leetcode-cn.com/problems/maximum-binary-tree-ii) | 最大二叉树 II |  | `树`,`二叉树` | 中等 |  |  |
| [0999](https://leetcode-cn.com/problems/available-captures-for-rook) | 可以被一步捕获的棋子数 |  | `数组`,`矩阵`,`模拟` | 简单 |  |  |
| [1000](https://leetcode-cn.com/problems/minimum-cost-to-merge-stones) | 合并石头的最低成本 |  | `数组`,`动态规划` | 困难 |  |  |
| [1001](https://leetcode-cn.com/problems/grid-illumination) | 网格照明 |  | `数组`,`哈希表` | 困难 |  |  |
| [1002](https://leetcode-cn.com/problems/find-common-characters) | 查找常用字符 |  | `数组`,`哈希表`,`字符串` | 简单 |  |  |
| [1003](https://leetcode-cn.com/problems/check-if-word-is-valid-after-substitutions) | 检查替换后的词是否有效 |  | `栈`,`字符串` | 中等 |  |  |
| [1004](https://leetcode-cn.com/problems/max-consecutive-ones-iii) | 最大连续1的个数 III |  | `数组`,`二分查找`,`前缀和`,`滑动窗口` | 中等 |  |  |
| [1005](https://leetcode-cn.com/problems/maximize-sum-of-array-after-k-negations) | K 次取反后最大化的数组和 |  | `贪心`,`数组`,`排序` | 简单 |  |  |
| [1006](https://leetcode-cn.com/problems/clumsy-factorial) | 笨阶乘 |  | `栈`,`数学`,`模拟` | 中等 |  |  |
| [1007](https://leetcode-cn.com/problems/minimum-domino-rotations-for-equal-row) | 行相等的最少多米诺旋转 |  | `贪心`,`数组` | 中等 |  |  |
| [1008](https://leetcode-cn.com/problems/construct-binary-search-tree-from-preorder-traversal) | 前序遍历构造二叉搜索树 |  | `栈`,`树`,`二叉搜索树`,`数组`,`二叉树`,`单调栈` | 中等 |  |  |
| [1009](https://leetcode-cn.com/problems/complement-of-base-10-integer) | 十进制整数的反码 |  | `位运算` | 简单 |  |  |
| [1010](https://leetcode-cn.com/problems/pairs-of-songs-with-total-durations-divisible-by-60) | 总持续时间可被 60 整除的歌曲 |  | `数组`,`哈希表`,`计数` | 中等 |  |  |
| [1011](https://leetcode-cn.com/problems/capacity-to-ship-packages-within-d-days) | 在 D 天内送达包裹的能力 |  | `贪心`,`数组`,`二分查找` | 中等 |  |  |
| [1012](https://leetcode-cn.com/problems/numbers-with-repeated-digits) | 至少有 1 位重复的数字 |  | `数学`,`动态规划` | 困难 |  |  |
| [1013](https://leetcode-cn.com/problems/partition-array-into-three-parts-with-equal-sum) | 将数组分成和相等的三个部分 |  | `贪心`,`数组` | 简单 |  |  |
| [1014](https://leetcode-cn.com/problems/best-sightseeing-pair) | 最佳观光组合 |  | `数组`,`动态规划` | 中等 |  |  |
| [1015](https://leetcode-cn.com/problems/smallest-integer-divisible-by-k) | 可被 K 整除的最小整数 |  | `哈希表`,`数学` | 中等 |  |  |
| [1016](https://leetcode-cn.com/problems/binary-string-with-substrings-representing-1-to-n) | 子串能表示从 1 到 N 数字的二进制串 |  | `字符串` | 中等 |  |  |
| [1017](https://leetcode-cn.com/problems/convert-to-base-2) | 负二进制转换 |  | `数学` | 中等 |  |  |
| [1018](https://leetcode-cn.com/problems/binary-prefix-divisible-by-5) | 可被 5 整除的二进制前缀 |  | `数组` | 简单 |  |  |
| [1019](https://leetcode-cn.com/problems/next-greater-node-in-linked-list) | 链表中的下一个更大节点 |  | `栈`,`数组`,`链表`,`单调栈` | 中等 |  |  |
| [1020](https://leetcode-cn.com/problems/number-of-enclaves) | 飞地的数量 |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`数组`,`矩阵` | 中等 |  |  |
| [1021](https://leetcode-cn.com/problems/remove-outermost-parentheses) | 删除最外层的括号 |  | `栈`,`字符串` | 简单 |  |  |
| [1022](https://leetcode-cn.com/problems/sum-of-root-to-leaf-binary-numbers) | 从根到叶的二进制数之和 |  | `树`,`深度优先搜索`,`二叉树` | 简单 |  |  |
| [1023](https://leetcode-cn.com/problems/camelcase-matching) | 驼峰式匹配 |  | `字典树`,`双指针`,`字符串`,`字符串匹配` | 中等 |  |  |
| [1024](https://leetcode-cn.com/problems/video-stitching) | 视频拼接 |  | `贪心`,`数组`,`动态规划` | 中等 |  |  |
| [1025](https://leetcode-cn.com/problems/divisor-game) | 除数博弈 |  | `脑筋急转弯`,`数学`,`动态规划`,`博弈` | 简单 |  |  |
| [1026](https://leetcode-cn.com/problems/maximum-difference-between-node-and-ancestor) | 节点与其祖先之间的最大差值 |  | `树`,`深度优先搜索`,`二叉树` | 中等 |  |  |
| [1027](https://leetcode-cn.com/problems/longest-arithmetic-subsequence) | 最长等差数列 |  | `数组`,`哈希表`,`二分查找`,`动态规划` | 中等 |  |  |
| [1028](https://leetcode-cn.com/problems/recover-a-tree-from-preorder-traversal) | 从先序遍历还原二叉树 |  | `树`,`深度优先搜索`,`字符串`,`二叉树` | 困难 |  |  |
| [1029](https://leetcode-cn.com/problems/two-city-scheduling) | 两地调度 |  | `贪心`,`数组`,`排序` | 中等 |  |  |
| [1030](https://leetcode-cn.com/problems/matrix-cells-in-distance-order) | 距离顺序排列矩阵单元格 |  | `几何`,`数组`,`数学`,`矩阵`,`排序` | 简单 |  |  |
| [1031](https://leetcode-cn.com/problems/maximum-sum-of-two-non-overlapping-subarrays) | 两个非重叠子数组的最大和 |  | `数组`,`动态规划`,`滑动窗口` | 中等 |  |  |
| [1032](https://leetcode-cn.com/problems/stream-of-characters) | 字符流 |  | `设计`,`字典树`,`数组`,`字符串`,`数据流` | 困难 |  |  |
| [1033](https://leetcode-cn.com/problems/moving-stones-until-consecutive) | 移动石子直到连续 |  | `脑筋急转弯`,`数学` | 简单 |  |  |
| [1034](https://leetcode-cn.com/problems/coloring-a-border) | 边框着色 |  | `深度优先搜索`,`广度优先搜索`,`数组`,`矩阵` | 中等 |  |  |
| [1035](https://leetcode-cn.com/problems/uncrossed-lines) | 不相交的线 |  | `数组`,`动态规划` | 中等 |  |  |
| [1036](https://leetcode-cn.com/problems/escape-a-large-maze) | 逃离大迷宫 |  | `深度优先搜索`,`广度优先搜索`,`数组`,`哈希表` | 困难 |  |  |
| [1037](https://leetcode-cn.com/problems/valid-boomerang) | 有效的回旋镖 |  | `几何`,`数学` | 简单 |  |  |
| [1038](https://leetcode-cn.com/problems/binary-search-tree-to-greater-sum-tree) | 把二叉搜索树转换为累加树 |  | `树`,`深度优先搜索`,`二叉搜索树`,`二叉树` | 中等 |  |  |
| [1039](https://leetcode-cn.com/problems/minimum-score-triangulation-of-polygon) | 多边形三角剖分的最低得分 |  | `数组`,`动态规划` | 中等 |  |  |
| [1040](https://leetcode-cn.com/problems/moving-stones-until-consecutive-ii) | 移动石子直到连续 II |  | `数组`,`数学`,`双指针`,`排序` | 中等 |  |  |
| [1041](https://leetcode-cn.com/problems/robot-bounded-in-circle) | 困于环中的机器人 |  | `数学`,`字符串`,`模拟` | 中等 |  |  |
| [1042](https://leetcode-cn.com/problems/flower-planting-with-no-adjacent) | 不邻接植花 |  | `深度优先搜索`,`广度优先搜索`,`图` | 中等 |  |  |
| [1043](https://leetcode-cn.com/problems/partition-array-for-maximum-sum) | 分隔数组以得到最大和 |  | `数组`,`动态规划` | 中等 |  |  |
| [1044](https://leetcode-cn.com/problems/longest-duplicate-substring) | 最长重复子串 |  | `字符串`,`二分查找`,`后缀数组`,`滑动窗口`,`哈希函数`,`滚动哈希` | 困难 |  |  |
| [1045](https://leetcode-cn.com/problems/customers-who-bought-all-products) | 买下所有产品的客户 |  | `数据库` | 中等 | 🔒 |  |
| [1046](https://leetcode-cn.com/problems/last-stone-weight) | 最后一块石头的重量 |  | `数组`,`堆（优先队列）` | 简单 |  |  |
| [1047](https://leetcode-cn.com/problems/remove-all-adjacent-duplicates-in-string) | 删除字符串中的所有相邻重复项 |  | `栈`,`字符串` | 简单 |  |  |
| [1048](https://leetcode-cn.com/problems/longest-string-chain) | 最长字符串链 |  | `数组`,`哈希表`,`双指针`,`字符串`,`动态规划` | 中等 |  |  |
| [1049](https://leetcode-cn.com/problems/last-stone-weight-ii) | 最后一块石头的重量 II |  | `数组`,`动态规划` | 中等 |  |  |
| [1050](https://leetcode-cn.com/problems/actors-and-directors-who-cooperated-at-least-three-times) | 合作过至少三次的演员和导演 |  | `数据库` | 简单 | 🔒 |  |
| [1051](https://leetcode-cn.com/problems/height-checker) | 高度检查器 |  | `数组`,`计数排序`,`排序` | 简单 |  |  |
| [1052](https://leetcode-cn.com/problems/grumpy-bookstore-owner) | 爱生气的书店老板 |  | `数组`,`滑动窗口` | 中等 |  |  |
| [1053](https://leetcode-cn.com/problems/previous-permutation-with-one-swap) | 交换一次的先前排列 |  | `贪心`,`数组` | 中等 |  |  |
| [1054](https://leetcode-cn.com/problems/distant-barcodes) | 距离相等的条形码 |  | `贪心`,`数组`,`哈希表`,`计数`,`排序`,`堆（优先队列）` | 中等 |  |  |
| [1055](https://leetcode-cn.com/problems/shortest-way-to-form-string) | 形成字符串的最短路径 |  | `贪心`,`字符串`,`动态规划` | 中等 | 🔒 |  |
| [1057](https://leetcode-cn.com/problems/campus-bikes) | 校园自行车分配 |  | `贪心`,`数组`,`排序` | 中等 | 🔒 |  |
| [1058](https://leetcode-cn.com/problems/minimize-rounding-error-to-meet-target) | 最小化舍入误差以满足目标 |  | `贪心`,`数组`,`数学`,`字符串` | 中等 | 🔒 |  |
| [1059](https://leetcode-cn.com/problems/all-paths-from-source-lead-to-destination) | 从始点到终点的所有路径 |  | `深度优先搜索`,`图` | 中等 | 🔒 |  |
| [1060](https://leetcode-cn.com/problems/missing-element-in-sorted-array) | 有序数组中的缺失元素 |  | `数组`,`二分查找` | 中等 | 🔒 |  |
| [1061](https://leetcode-cn.com/problems/lexicographically-smallest-equivalent-string) | 按字典序排列最小的等效字符串 |  | `并查集`,`字符串` | 中等 | 🔒 |  |
| [1062](https://leetcode-cn.com/problems/longest-repeating-substring) | 最长重复子串 |  | `字符串`,`二分查找`,`动态规划`,`后缀数组`,`哈希函数`,`滚动哈希` | 中等 | 🔒 |  |
| [1063](https://leetcode-cn.com/problems/number-of-valid-subarrays) | 有效子数组的数目 |  | `栈`,`数组`,`单调栈` | 困难 | 🔒 |  |
| [1064](https://leetcode-cn.com/problems/fixed-point) | 不动点 |  | `数组`,`二分查找` | 简单 | 🔒 |  |
| [1065](https://leetcode-cn.com/problems/index-pairs-of-a-string) | 字符串的索引对 |  | `字典树`,`数组`,`字符串`,`排序` | 简单 | 🔒 |  |
| [1066](https://leetcode-cn.com/problems/campus-bikes-ii) | 校园自行车分配 II |  | `位运算`,`数组`,`动态规划`,`回溯`,`状态压缩` | 中等 | 🔒 |  |
| [1067](https://leetcode-cn.com/problems/digit-count-in-range) | 范围内的数字计数 |  | `数学`,`动态规划` | 困难 | 🔒 |  |
| [1068](https://leetcode-cn.com/problems/product-sales-analysis-i) | 产品销售分析 I |  | `数据库` | 简单 | 🔒 |  |
| [1069](https://leetcode-cn.com/problems/product-sales-analysis-ii) | 产品销售分析 II |  | `数据库` | 简单 | 🔒 |  |
| [1070](https://leetcode-cn.com/problems/product-sales-analysis-iii) | 产品销售分析 III |  | `数据库` | 中等 | 🔒 |  |
| [1071](https://leetcode-cn.com/problems/greatest-common-divisor-of-strings) | 字符串的最大公因子 |  | `数学`,`字符串` | 简单 |  |  |
| [1072](https://leetcode-cn.com/problems/flip-columns-for-maximum-number-of-equal-rows) | 按列翻转得到最大值等行数 |  | `数组`,`哈希表`,`矩阵` | 中等 |  |  |
| [1073](https://leetcode-cn.com/problems/adding-two-negabinary-numbers) | 负二进制数相加 |  | `数组`,`数学` | 中等 |  |  |
| [1074](https://leetcode-cn.com/problems/number-of-submatrices-that-sum-to-target) | 元素和为目标值的子矩阵数量 |  | `数组`,`哈希表`,`矩阵`,`前缀和` | 困难 |  |  |
| [1075](https://leetcode-cn.com/problems/project-employees-i) | 项目员工 I |  | `数据库` | 简单 | 🔒 |  |
| [1076](https://leetcode-cn.com/problems/project-employees-ii) | 项目员工II |  | `数据库` | 简单 | 🔒 |  |
| [1077](https://leetcode-cn.com/problems/project-employees-iii) | 项目员工 III |  | `数据库` | 中等 | 🔒 |  |
| [1078](https://leetcode-cn.com/problems/occurrences-after-bigram) | Bigram 分词 |  | `字符串` | 简单 |  |  |
| [1079](https://leetcode-cn.com/problems/letter-tile-possibilities) | 活字印刷 |  | `字符串`,`回溯` | 中等 |  |  |
| [1080](https://leetcode-cn.com/problems/insufficient-nodes-in-root-to-leaf-paths) | 根到叶路径上的不足节点 |  | `树`,`深度优先搜索`,`二叉树` | 中等 |  |  |
| [1081](https://leetcode-cn.com/problems/smallest-subsequence-of-distinct-characters) | 不同字符的最小子序列 |  | `栈`,`贪心`,`字符串`,`单调栈` | 中等 |  |  |
| [1082](https://leetcode-cn.com/problems/sales-analysis-i) | 销售分析 I |  | `数据库` | 简单 | 🔒 |  |
| [1083](https://leetcode-cn.com/problems/sales-analysis-ii) | 销售分析 II |  | `数据库` | 简单 | 🔒 |  |
| [1084](https://leetcode-cn.com/problems/sales-analysis-iii) | 销售分析III |  | `数据库` | 简单 | 🔒 |  |
| [1085](https://leetcode-cn.com/problems/sum-of-digits-in-the-minimum-number) | 最小元素各数位之和 |  | `数组`,`数学` | 简单 | 🔒 |  |
| [1086](https://leetcode-cn.com/problems/high-five) | 前五科的均分 |  | `数组`,`哈希表`,`排序` | 简单 | 🔒 |  |
| [1087](https://leetcode-cn.com/problems/brace-expansion) | 花括号展开 |  | `广度优先搜索`,`字符串`,`回溯` | 中等 | 🔒 |  |
| [1088](https://leetcode-cn.com/problems/confusing-number-ii) | 易混淆数 II |  | `数学`,`回溯` | 困难 | 🔒 |  |
| [1089](https://leetcode-cn.com/problems/duplicate-zeros) | 复写零 |  | `数组`,`双指针` | 简单 |  |  |
| [1090](https://leetcode-cn.com/problems/largest-values-from-labels) | 受标签影响的最大值 |  | `贪心`,`数组`,`哈希表`,`计数`,`排序` | 中等 |  |  |
| [1091](https://leetcode-cn.com/problems/shortest-path-in-binary-matrix) | 二进制矩阵中的最短路径 |  | `广度优先搜索`,`数组`,`矩阵` | 中等 |  |  |
| [1092](https://leetcode-cn.com/problems/shortest-common-supersequence) | 最短公共超序列 |  | `字符串`,`动态规划` | 困难 |  |  |
| [1093](https://leetcode-cn.com/problems/statistics-from-a-large-sample) | 大样本统计 |  | `数学`,`双指针`,`概率与统计` | 中等 |  |  |
| [1094](https://leetcode-cn.com/problems/car-pooling) | 拼车 |  | `数组`,`前缀和`,`排序`,`模拟`,`堆（优先队列）` | 中等 |  |  |
| [1095](https://leetcode-cn.com/problems/find-in-mountain-array) | 山脉数组中查找目标值 |  | `数组`,`二分查找`,`交互` | 困难 |  |  |
| [1096](https://leetcode-cn.com/problems/brace-expansion-ii) | 花括号展开 II |  | `栈`,`广度优先搜索`,`字符串`,`回溯` | 困难 |  |  |
| [1097](https://leetcode-cn.com/problems/game-play-analysis-v) | 游戏玩法分析 V |  | `数据库` | 困难 | 🔒 |  |
| [1098](https://leetcode-cn.com/problems/unpopular-books) | 小众书籍 |  | `数据库` | 中等 | 🔒 |  |
| [1099](https://leetcode-cn.com/problems/two-sum-less-than-k) | 小于 K 的两数之和 |  | `数组`,`双指针`,`二分查找`,`排序` | 简单 | 🔒 |  |
| [1100](https://leetcode-cn.com/problems/find-k-length-substrings-with-no-repeated-characters) | 长度为 K 的无重复字符子串 |  | `哈希表`,`字符串`,`滑动窗口` | 中等 | 🔒 |  |
| [1101](https://leetcode-cn.com/problems/the-earliest-moment-when-everyone-become-friends) | 彼此熟识的最早时间 |  | `并查集`,`数组` | 中等 | 🔒 |  |
| [1102](https://leetcode-cn.com/problems/path-with-maximum-minimum-value) | 得分最高的路径 |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`数组`,`矩阵`,`堆（优先队列）` | 中等 | 🔒 |  |
| [1103](https://leetcode-cn.com/problems/distribute-candies-to-people) | 分糖果 II |  | `数学`,`模拟` | 简单 |  |  |
| [1104](https://leetcode-cn.com/problems/path-in-zigzag-labelled-binary-tree) | 二叉树寻路 |  | `树`,`数学`,`二叉树` | 中等 |  |  |
| [1105](https://leetcode-cn.com/problems/filling-bookcase-shelves) | 填充书架 |  | `数组`,`动态规划` | 中等 |  |  |
| [1106](https://leetcode-cn.com/problems/parsing-a-boolean-expression) | 解析布尔表达式 |  | `栈`,`递归`,`字符串` | 困难 |  |  |
| [1107](https://leetcode-cn.com/problems/new-users-daily-count) | 每日新用户统计 |  | `数据库` | 中等 | 🔒 |  |
| [1108](https://leetcode-cn.com/problems/defanging-an-ip-address) | IP 地址无效化 |  | `字符串` | 简单 |  |  |
| [1109](https://leetcode-cn.com/problems/corporate-flight-bookings) | 航班预订统计 |  | `数组`,`前缀和` | 中等 |  |  |
| [1110](https://leetcode-cn.com/problems/delete-nodes-and-return-forest) | 删点成林 |  | `树`,`深度优先搜索`,`二叉树` | 中等 |  |  |
| [1111](https://leetcode-cn.com/problems/maximum-nesting-depth-of-two-valid-parentheses-strings) | 有效括号的嵌套深度 |  | `栈`,`字符串` | 中等 |  |  |
| [1112](https://leetcode-cn.com/problems/highest-grade-for-each-student) | 每位学生的最高成绩 |  | `数据库` | 中等 | 🔒 |  |
| [1113](https://leetcode-cn.com/problems/reported-posts) | 报告的记录 |  | `数据库` | 简单 | 🔒 |  |
| [1114](https://leetcode-cn.com/problems/print-in-order) | 按序打印 |  | `多线程` | 简单 |  |  |
| [1115](https://leetcode-cn.com/problems/print-foobar-alternately) | 交替打印FooBar |  | `多线程` | 中等 |  |  |
| [1116](https://leetcode-cn.com/problems/print-zero-even-odd) | 打印零与奇偶数 |  | `多线程` | 中等 |  |  |
| [1117](https://leetcode-cn.com/problems/building-h2o) | H2O 生成 |  | `多线程` | 中等 |  |  |
| [1118](https://leetcode-cn.com/problems/number-of-days-in-a-month) | 一月有多少天 |  | `数学` | 简单 | 🔒 |  |
| [1119](https://leetcode-cn.com/problems/remove-vowels-from-a-string) | 删去字符串中的元音 |  | `字符串` | 简单 | 🔒 |  |
| [1120](https://leetcode-cn.com/problems/maximum-average-subtree) | 子树的最大平均值 |  | `树`,`深度优先搜索`,`二叉树` | 中等 | 🔒 |  |
| [1121](https://leetcode-cn.com/problems/divide-array-into-increasing-sequences) | 将数组分成几个递增序列 |  | `贪心`,`数组` | 困难 | 🔒 |  |
| [1122](https://leetcode-cn.com/problems/relative-sort-array) | 数组的相对排序 |  | `数组`,`哈希表`,`计数排序`,`排序` | 简单 |  |  |
| [1123](https://leetcode-cn.com/problems/lowest-common-ancestor-of-deepest-leaves) | 最深叶节点的最近公共祖先 |  | `树`,`深度优先搜索`,`广度优先搜索`,`哈希表`,`二叉树` | 中等 |  |  |
| [1124](https://leetcode-cn.com/problems/longest-well-performing-interval) | 表现良好的最长时间段 |  | `栈`,`数组`,`哈希表`,`前缀和`,`单调栈` | 中等 |  |  |
| [1125](https://leetcode-cn.com/problems/smallest-sufficient-team) | 最小的必要团队 |  | `位运算`,`数组`,`动态规划`,`状态压缩` | 困难 |  |  |
| [1126](https://leetcode-cn.com/problems/active-businesses) | 查询活跃业务 |  | `数据库` | 中等 | 🔒 |  |
| [1127](https://leetcode-cn.com/problems/user-purchase-platform) | 用户购买平台 |  | `数据库` | 困难 | 🔒 |  |
| [1128](https://leetcode-cn.com/problems/number-of-equivalent-domino-pairs) | 等价多米诺骨牌对的数量 |  | `数组`,`哈希表`,`计数` | 简单 |  |  |
| [1129](https://leetcode-cn.com/problems/shortest-path-with-alternating-colors) | 颜色交替的最短路径 |  | `广度优先搜索`,`图` | 中等 |  |  |
| [1130](https://leetcode-cn.com/problems/minimum-cost-tree-from-leaf-values) | 叶值的最小代价生成树 |  | `栈`,`贪心`,`动态规划`,`单调栈` | 中等 |  |  |
| [1131](https://leetcode-cn.com/problems/maximum-of-absolute-value-expression) | 绝对值表达式的最大值 |  | `数组`,`数学` | 中等 |  |  |
| [1132](https://leetcode-cn.com/problems/reported-posts-ii) | 报告的记录 II |  | `数据库` | 中等 | 🔒 |  |
| [1133](https://leetcode-cn.com/problems/largest-unique-number) | 最大唯一数 |  | `数组`,`哈希表`,`排序` | 简单 | 🔒 |  |
| [1134](https://leetcode-cn.com/problems/armstrong-number) | 阿姆斯特朗数 |  | `数学` | 简单 | 🔒 |  |
| [1135](https://leetcode-cn.com/problems/connecting-cities-with-minimum-cost) | 最低成本联通所有城市 |  | `并查集`,`图`,`最小生成树`,`堆（优先队列）` | 中等 | 🔒 |  |
| [1136](https://leetcode-cn.com/problems/parallel-courses) | 平行课程 |  | `图`,`拓扑排序` | 中等 | 🔒 |  |
| [1137](https://leetcode-cn.com/problems/n-th-tribonacci-number) | 第 N 个泰波那契数 |  | `记忆化搜索`,`数学`,`动态规划` | 简单 |  |  |
| [1138](https://leetcode-cn.com/problems/alphabet-board-path) | 字母板上的路径 |  | `哈希表`,`字符串` | 中等 |  |  |
| [1139](https://leetcode-cn.com/problems/largest-1-bordered-square) | 最大的以 1 为边界的正方形 |  | `数组`,`动态规划`,`矩阵` | 中等 |  |  |
| [1140](https://leetcode-cn.com/problems/stone-game-ii) | 石子游戏 II |  | `数组`,`数学`,`动态规划`,`博弈` | 中等 |  |  |
| [1141](https://leetcode-cn.com/problems/user-activity-for-the-past-30-days-i) | 查询近30天活跃用户数 |  | `数据库` | 简单 | 🔒 |  |
| [1142](https://leetcode-cn.com/problems/user-activity-for-the-past-30-days-ii) | 过去30天的用户活动 II |  | `数据库` | 简单 | 🔒 |  |
| [1143](https://leetcode-cn.com/problems/longest-common-subsequence) | 最长公共子序列 |  | `字符串`,`动态规划` | 中等 |  |  |
| [1144](https://leetcode-cn.com/problems/decrease-elements-to-make-array-zigzag) | 递减元素使数组呈锯齿状 |  | `贪心`,`数组` | 中等 |  |  |
| [1145](https://leetcode-cn.com/problems/binary-tree-coloring-game) | 二叉树着色游戏 |  | `树`,`深度优先搜索`,`二叉树` | 中等 |  |  |
| [1146](https://leetcode-cn.com/problems/snapshot-array) | 快照数组 |  | `设计`,`数组`,`哈希表`,`二分查找` | 中等 |  |  |
| [1147](https://leetcode-cn.com/problems/longest-chunked-palindrome-decomposition) | 段式回文 |  | `贪心`,`双指针`,`字符串`,`动态规划`,`哈希函数`,`滚动哈希` | 困难 |  |  |
| [1148](https://leetcode-cn.com/problems/article-views-i) | 文章浏览 I |  | `数据库` | 简单 | 🔒 |  |
| [1149](https://leetcode-cn.com/problems/article-views-ii) | 文章浏览 II |  | `数据库` | 中等 | 🔒 |  |
| [1150](https://leetcode-cn.com/problems/check-if-a-number-is-majority-element-in-a-sorted-array) | 检查一个数是否在数组中占绝大多数 |  | `数组`,`二分查找` | 简单 | 🔒 |  |
| [1151](https://leetcode-cn.com/problems/minimum-swaps-to-group-all-1s-together) | 最少交换次数来组合所有的 1 |  | `数组`,`滑动窗口` | 中等 | 🔒 |  |
| [1152](https://leetcode-cn.com/problems/analyze-user-website-visit-pattern) | 用户网站访问行为分析 |  | `数组`,`哈希表`,`排序` | 中等 | 🔒 |  |
| [1153](https://leetcode-cn.com/problems/string-transforms-into-another-string) | 字符串转化 |  | `哈希表`,`字符串` | 困难 | 🔒 |  |
| [1154](https://leetcode-cn.com/problems/day-of-the-year) | 一年中的第几天 |  | `数学`,`字符串` | 简单 |  |  |
| [1155](https://leetcode-cn.com/problems/number-of-dice-rolls-with-target-sum) | 掷骰子的N种方法 |  | `动态规划` | 中等 |  |  |
| [1156](https://leetcode-cn.com/problems/swap-for-longest-repeated-character-substring) | 单字符重复子串的最大长度 |  | `字符串`,`滑动窗口` | 中等 |  |  |
| [1157](https://leetcode-cn.com/problems/online-majority-element-in-subarray) | 子数组中占绝大多数的元素 |  | `设计`,`树状数组`,`线段树`,`数组`,`二分查找` | 困难 |  |  |
| [1158](https://leetcode-cn.com/problems/market-analysis-i) | 市场分析 I |  | `数据库` | 中等 | 🔒 |  |
| [1159](https://leetcode-cn.com/problems/market-analysis-ii) | 市场分析 II |  | `数据库` | 困难 | 🔒 |  |
| [1160](https://leetcode-cn.com/problems/find-words-that-can-be-formed-by-characters) | 拼写单词 |  | `数组`,`哈希表`,`字符串` | 简单 |  |  |
| [1161](https://leetcode-cn.com/problems/maximum-level-sum-of-a-binary-tree) | 最大层内元素和 |  | `树`,`广度优先搜索`,`二叉树` | 中等 |  |  |
| [1162](https://leetcode-cn.com/problems/as-far-from-land-as-possible) | 地图分析 |  | `广度优先搜索`,`数组`,`动态规划`,`矩阵` | 中等 |  |  |
| [1163](https://leetcode-cn.com/problems/last-substring-in-lexicographical-order) | 按字典序排在最后的子串 |  | `双指针`,`字符串` | 困难 |  |  |
| [1164](https://leetcode-cn.com/problems/product-price-at-a-given-date) | 指定日期的产品价格 |  | `数据库` | 中等 | 🔒 |  |
| [1165](https://leetcode-cn.com/problems/single-row-keyboard) | 单行键盘 |  | `哈希表`,`字符串` | 简单 | 🔒 |  |
| [1166](https://leetcode-cn.com/problems/design-file-system) | 设计文件系统 |  | `设计`,`字典树`,`哈希表`,`字符串` | 中等 | 🔒 |  |
| [1167](https://leetcode-cn.com/problems/minimum-cost-to-connect-sticks) | 连接棒材的最低费用 |  | `贪心`,`数组`,`堆（优先队列）` | 中等 | 🔒 |  |
| [1168](https://leetcode-cn.com/problems/optimize-water-distribution-in-a-village) | 水资源分配优化 |  | `并查集`,`图`,`最小生成树` | 困难 | 🔒 |  |
| [1169](https://leetcode-cn.com/problems/invalid-transactions) | 查询无效交易 |  | `数组`,`哈希表`,`字符串`,`排序` | 中等 |  |  |
| [1170](https://leetcode-cn.com/problems/compare-strings-by-frequency-of-the-smallest-character) | 比较字符串最小字母出现频次 |  | `数组`,`哈希表`,`字符串`,`二分查找`,`排序` | 中等 |  |  |
| [1171](https://leetcode-cn.com/problems/remove-zero-sum-consecutive-nodes-from-linked-list) | 从链表中删去总和值为零的连续节点 |  | `哈希表`,`链表` | 中等 |  |  |
| [1172](https://leetcode-cn.com/problems/dinner-plate-stacks) | 餐盘栈 |  | `栈`,`设计`,`哈希表`,`堆（优先队列）` | 困难 |  |  |
| [1173](https://leetcode-cn.com/problems/immediate-food-delivery-i) | 即时食物配送 I |  | `数据库` | 简单 | 🔒 |  |
| [1174](https://leetcode-cn.com/problems/immediate-food-delivery-ii) | 即时食物配送 II |  | `数据库` | 中等 | 🔒 |  |
| [1175](https://leetcode-cn.com/problems/prime-arrangements) | 质数排列 |  | `数学` | 简单 |  |  |
| [1176](https://leetcode-cn.com/problems/diet-plan-performance) | 健身计划评估 |  | `数组`,`滑动窗口` | 简单 | 🔒 |  |
| [1177](https://leetcode-cn.com/problems/can-make-palindrome-from-substring) | 构建回文串检测 |  | `位运算`,`哈希表`,`字符串`,`前缀和` | 中等 |  |  |
| [1178](https://leetcode-cn.com/problems/number-of-valid-words-for-each-puzzle) | 猜字谜 |  | `位运算`,`字典树`,`数组`,`哈希表`,`字符串` | 困难 |  |  |
| [1179](https://leetcode-cn.com/problems/reformat-department-table) | 重新格式化部门表 |  | `数据库` | 简单 |  |  |
| [1180](https://leetcode-cn.com/problems/count-substrings-with-only-one-distinct-letter) | 统计只含单一字母的子串 |  | `数学`,`字符串` | 简单 | 🔒 |  |
| [1181](https://leetcode-cn.com/problems/before-and-after-puzzle) | 前后拼接 |  | `数组`,`哈希表`,`字符串`,`排序` | 中等 | 🔒 |  |
| [1182](https://leetcode-cn.com/problems/shortest-distance-to-target-color) | 与目标颜色间的最短距离 |  | `数组`,`二分查找`,`动态规划` | 中等 | 🔒 |  |
| [1183](https://leetcode-cn.com/problems/maximum-number-of-ones) | 矩阵中 1 的最大数量 |  | `贪心`,`堆（优先队列）` | 困难 | 🔒 |  |
| [1184](https://leetcode-cn.com/problems/distance-between-bus-stops) | 公交站间的距离 |  | `数组` | 简单 |  |  |
| [1185](https://leetcode-cn.com/problems/day-of-the-week) | 一周中的第几天 |  | `数学` | 简单 |  |  |
| [1186](https://leetcode-cn.com/problems/maximum-subarray-sum-with-one-deletion) | 删除一次得到子数组最大和 |  | `数组`,`动态规划` | 中等 |  |  |
| [1187](https://leetcode-cn.com/problems/make-array-strictly-increasing) | 使数组严格递增 |  | `数组`,`二分查找`,`动态规划` | 困难 |  |  |
| [1188](https://leetcode-cn.com/problems/design-bounded-blocking-queue) | 设计有限阻塞队列 |  | `多线程` | 中等 | 🔒 |  |
| [1189](https://leetcode-cn.com/problems/maximum-number-of-balloons) | "气球" 的最大数量 |  | `哈希表`,`字符串`,`计数` | 简单 |  |  |
| [1190](https://leetcode-cn.com/problems/reverse-substrings-between-each-pair-of-parentheses) | 反转每对括号间的子串 |  | `栈`,`字符串` | 中等 |  |  |
| [1191](https://leetcode-cn.com/problems/k-concatenation-maximum-sum) | K 次串联后最大子数组之和 |  | `数组`,`动态规划` | 中等 |  |  |
| [1192](https://leetcode-cn.com/problems/critical-connections-in-a-network) | 查找集群内的「关键连接」 |  | `深度优先搜索`,`图`,`双连通分量` | 困难 |  |  |
| [1193](https://leetcode-cn.com/problems/monthly-transactions-i) | 每月交易 I |  | `数据库` | 中等 | 🔒 |  |
| [1194](https://leetcode-cn.com/problems/tournament-winners) | 锦标赛优胜者 |  | `数据库` | 困难 | 🔒 |  |
| [1195](https://leetcode-cn.com/problems/fizz-buzz-multithreaded) | 交替打印字符串 |  | `多线程` | 中等 |  |  |
| [1196](https://leetcode-cn.com/problems/how-many-apples-can-you-put-into-the-basket) | 最多可以买到的苹果数量 |  | `贪心`,`数组`,`排序` | 简单 | 🔒 |  |
| [1197](https://leetcode-cn.com/problems/minimum-knight-moves) | 进击的骑士 |  | `广度优先搜索` | 中等 | 🔒 |  |
| [1198](https://leetcode-cn.com/problems/find-smallest-common-element-in-all-rows) | 找出所有行中最小公共元素 |  | `数组`,`哈希表`,`二分查找`,`计数`,`矩阵` | 中等 | 🔒 |  |
| [1199](https://leetcode-cn.com/problems/minimum-time-to-build-blocks) | 建造街区的最短时间 |  | `贪心`,`数学`,`堆（优先队列）` | 困难 | 🔒 |  |
| [1200](https://leetcode-cn.com/problems/minimum-absolute-difference) | 最小绝对差 |  | `数组`,`排序` | 简单 |  |  |
| [1201](https://leetcode-cn.com/problems/ugly-number-iii) | 丑数 III |  | `数学`,`二分查找`,`数论` | 中等 |  |  |
| [1202](https://leetcode-cn.com/problems/smallest-string-with-swaps) | 交换字符串中的元素 |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`哈希表`,`字符串` | 中等 |  |  |
| [1203](https://leetcode-cn.com/problems/sort-items-by-groups-respecting-dependencies) | 项目管理 |  | `深度优先搜索`,`广度优先搜索`,`图`,`拓扑排序` | 困难 |  |  |
| [1204](https://leetcode-cn.com/problems/last-person-to-fit-in-the-bus) | 最后一个能进入电梯的人 |  | `数据库` | 中等 | 🔒 |  |
| [1205](https://leetcode-cn.com/problems/monthly-transactions-ii) | 每月交易II |  | `数据库` | 中等 | 🔒 |  |
| [1206](https://leetcode-cn.com/problems/design-skiplist) | 设计跳表 |  | `设计`,`链表` | 困难 |  |  |
| [1207](https://leetcode-cn.com/problems/unique-number-of-occurrences) | 独一无二的出现次数 |  | `数组`,`哈希表` | 简单 |  |  |
| [1208](https://leetcode-cn.com/problems/get-equal-substrings-within-budget) | 尽可能使字符串相等 |  | `字符串`,`二分查找`,`前缀和`,`滑动窗口` | 中等 |  |  |
| [1209](https://leetcode-cn.com/problems/remove-all-adjacent-duplicates-in-string-ii) | 删除字符串中的所有相邻重复项 II |  | `栈`,`字符串` | 中等 |  |  |
| [1210](https://leetcode-cn.com/problems/minimum-moves-to-reach-target-with-rotations) | 穿过迷宫的最少移动次数 |  | `广度优先搜索`,`数组`,`矩阵` | 困难 |  |  |
| [1211](https://leetcode-cn.com/problems/queries-quality-and-percentage) | 查询结果的质量和占比 |  | `数据库` | 简单 | 🔒 |  |
| [1212](https://leetcode-cn.com/problems/team-scores-in-football-tournament) | 查询球队积分 |  | `数据库` | 中等 | 🔒 |  |
| [1213](https://leetcode-cn.com/problems/intersection-of-three-sorted-arrays) | 三个有序数组的交集 |  | `数组`,`哈希表`,`二分查找`,`计数` | 简单 | 🔒 |  |
| [1214](https://leetcode-cn.com/problems/two-sum-bsts) | 查找两棵二叉搜索树之和 |  | `栈`,`树`,`深度优先搜索`,`二叉搜索树`,`双指针`,`二分查找`,`二叉树` | 中等 | 🔒 |  |
| [1215](https://leetcode-cn.com/problems/stepping-numbers) | 步进数 |  | `广度优先搜索`,`回溯` | 中等 | 🔒 |  |
| [1216](https://leetcode-cn.com/problems/valid-palindrome-iii) | 验证回文字符串 III |  | `字符串`,`动态规划` | 困难 | 🔒 |  |
| [1217](https://leetcode-cn.com/problems/minimum-cost-to-move-chips-to-the-same-position) | 玩筹码 |  | `贪心`,`数组`,`数学` | 简单 |  |  |
| [1218](https://leetcode-cn.com/problems/longest-arithmetic-subsequence-of-given-difference) | 最长定差子序列 |  | `数组`,`哈希表`,`动态规划` | 中等 |  |  |
| [1219](https://leetcode-cn.com/problems/path-with-maximum-gold) | 黄金矿工 |  | `数组`,`回溯`,`矩阵` | 中等 |  |  |
| [1220](https://leetcode-cn.com/problems/count-vowels-permutation) | 统计元音字母序列的数目 |  | `动态规划` | 困难 |  |  |
| [1221](https://leetcode-cn.com/problems/split-a-string-in-balanced-strings) | 分割平衡字符串 |  | `贪心`,`字符串`,`计数` | 简单 |  |  |
| [1222](https://leetcode-cn.com/problems/queens-that-can-attack-the-king) | 可以攻击国王的皇后 |  | `数组`,`矩阵`,`模拟` | 中等 |  |  |
| [1223](https://leetcode-cn.com/problems/dice-roll-simulation) | 掷骰子模拟 |  | `数组`,`动态规划` | 困难 |  |  |
| [1224](https://leetcode-cn.com/problems/maximum-equal-frequency) | 最大相等频率 |  | `数组`,`哈希表` | 困难 |  |  |
| [1225](https://leetcode-cn.com/problems/report-contiguous-dates) | 报告系统状态的连续日期 |  | `数据库` | 困难 | 🔒 |  |
| [1226](https://leetcode-cn.com/problems/the-dining-philosophers) | 哲学家进餐 |  | `多线程` | 中等 |  |  |
| [1227](https://leetcode-cn.com/problems/airplane-seat-assignment-probability) | 飞机座位分配概率 |  | `脑筋急转弯`,`数学`,`动态规划`,`概率与统计` | 中等 |  |  |
| [1228](https://leetcode-cn.com/problems/missing-number-in-arithmetic-progression) | 等差数列中缺失的数字 |  | `数组`,`数学` | 简单 | 🔒 |  |
| [1229](https://leetcode-cn.com/problems/meeting-scheduler) | 安排会议日程 |  | `数组`,`双指针`,`排序` | 中等 | 🔒 |  |
| [1230](https://leetcode-cn.com/problems/toss-strange-coins) | 抛掷硬币 |  | `数学`,`动态规划`,`概率与统计` | 中等 | 🔒 |  |
| [1231](https://leetcode-cn.com/problems/divide-chocolate) | 分享巧克力 |  | `数组`,`二分查找` | 困难 | 🔒 |  |
| [1232](https://leetcode-cn.com/problems/check-if-it-is-a-straight-line) | 缀点成线 |  | `几何`,`数组`,`数学` | 简单 |  |  |
| [1233](https://leetcode-cn.com/problems/remove-sub-folders-from-the-filesystem) | 删除子文件夹 |  | `字典树`,`数组`,`字符串` | 中等 |  |  |
| [1234](https://leetcode-cn.com/problems/replace-the-substring-for-balanced-string) | 替换子串得到平衡字符串 |  | `字符串`,`滑动窗口` | 中等 |  |  |
| [1235](https://leetcode-cn.com/problems/maximum-profit-in-job-scheduling) | 规划兼职工作 |  | `数组`,`二分查找`,`动态规划`,`排序` | 困难 |  |  |
| [1236](https://leetcode-cn.com/problems/web-crawler) | 网络爬虫 |  | `深度优先搜索`,`广度优先搜索`,`字符串`,`交互` | 中等 | 🔒 |  |
| [1237](https://leetcode-cn.com/problems/find-positive-integer-solution-for-a-given-equation) | 找出给定方程的正整数解 |  | `数学`,`双指针`,`二分查找`,`交互` | 中等 |  |  |
| [1238](https://leetcode-cn.com/problems/circular-permutation-in-binary-representation) | 循环码排列 |  | `位运算`,`数学`,`回溯` | 中等 |  |  |
| [1239](https://leetcode-cn.com/problems/maximum-length-of-a-concatenated-string-with-unique-characters) | 串联字符串的最大长度 |  | `位运算`,`数组`,`字符串`,`回溯` | 中等 |  |  |
| [1240](https://leetcode-cn.com/problems/tiling-a-rectangle-with-the-fewest-squares) | 铺瓷砖 |  | `动态规划`,`回溯` | 困难 |  |  |
| [1241](https://leetcode-cn.com/problems/number-of-comments-per-post) | 每个帖子的评论数 |  | `数据库` | 简单 | 🔒 |  |
| [1242](https://leetcode-cn.com/problems/web-crawler-multithreaded) | 多线程网页爬虫 |  | `深度优先搜索`,`广度优先搜索`,`多线程` | 中等 | 🔒 |  |
| [1243](https://leetcode-cn.com/problems/array-transformation) | 数组变换 |  | `数组`,`模拟` | 简单 | 🔒 |  |
| [1244](https://leetcode-cn.com/problems/design-a-leaderboard) | 力扣排行榜 |  | `设计`,`哈希表`,`排序` | 中等 | 🔒 |  |
| [1245](https://leetcode-cn.com/problems/tree-diameter) | 树的直径 |  | `树`,`深度优先搜索`,`广度优先搜索` | 中等 | 🔒 |  |
| [1246](https://leetcode-cn.com/problems/palindrome-removal) | 删除回文子数组 |  | `数组`,`动态规划` | 困难 | 🔒 |  |
| [1247](https://leetcode-cn.com/problems/minimum-swaps-to-make-strings-equal) | 交换字符使得字符串相同 |  | `贪心`,`数学`,`字符串` | 中等 |  |  |
| [1248](https://leetcode-cn.com/problems/count-number-of-nice-subarrays) | 统计「优美子数组」 |  | `数组`,`哈希表`,`数学`,`滑动窗口` | 中等 |  |  |
| [1249](https://leetcode-cn.com/problems/minimum-remove-to-make-valid-parentheses) | 移除无效的括号 |  | `栈`,`字符串` | 中等 |  |  |
| [1250](https://leetcode-cn.com/problems/check-if-it-is-a-good-array) | 检查「好数组」 |  | `数组`,`数学`,`数论` | 困难 |  |  |
| [1251](https://leetcode-cn.com/problems/average-selling-price) | 平均售价 |  | `数据库` | 简单 | 🔒 |  |
| [1252](https://leetcode-cn.com/problems/cells-with-odd-values-in-a-matrix) | 奇数值单元格的数目 |  | `数组`,`数学`,`模拟` | 简单 |  |  |
| [1253](https://leetcode-cn.com/problems/reconstruct-a-2-row-binary-matrix) | 重构 2 行二进制矩阵 |  | `贪心`,`数组`,`矩阵` | 中等 |  |  |
| [1254](https://leetcode-cn.com/problems/number-of-closed-islands) | 统计封闭岛屿的数目 |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`数组`,`矩阵` | 中等 |  |  |
| [1255](https://leetcode-cn.com/problems/maximum-score-words-formed-by-letters) | 得分最高的单词集合 |  | `位运算`,`数组`,`字符串`,`动态规划`,`回溯`,`状态压缩` | 困难 |  |  |
| [1256](https://leetcode-cn.com/problems/encode-number) | 加密数字 |  | `位运算`,`数学`,`字符串` | 中等 | 🔒 |  |
| [1257](https://leetcode-cn.com/problems/smallest-common-region) | 最小公共区域 |  | `树`,`深度优先搜索`,`广度优先搜索`,`数组`,`哈希表`,`字符串` | 中等 | 🔒 |  |
| [1258](https://leetcode-cn.com/problems/synonymous-sentences) | 近义词句子 |  | `并查集`,`数组`,`哈希表`,`字符串`,`回溯` | 中等 | 🔒 |  |
| [1259](https://leetcode-cn.com/problems/handshakes-that-dont-cross) | 不相交的握手 |  | `数学`,`动态规划` | 困难 | 🔒 |  |
| [1260](https://leetcode-cn.com/problems/shift-2d-grid) | 二维网格迁移 |  | `数组`,`矩阵`,`模拟` | 简单 |  |  |
| [1261](https://leetcode-cn.com/problems/find-elements-in-a-contaminated-binary-tree) | 在受污染的二叉树中查找元素 |  | `树`,`深度优先搜索`,`广度优先搜索`,`设计`,`二叉树` | 中等 |  |  |
| [1262](https://leetcode-cn.com/problems/greatest-sum-divisible-by-three) | 可被三整除的最大和 |  | `贪心`,`数组`,`动态规划` | 中等 |  |  |
| [1263](https://leetcode-cn.com/problems/minimum-moves-to-move-a-box-to-their-target-location) | 推箱子 |  | `广度优先搜索`,`数组`,`矩阵`,`堆（优先队列）` | 困难 |  |  |
| [1264](https://leetcode-cn.com/problems/page-recommendations) | 页面推荐 |  | `数据库` | 中等 | 🔒 |  |
| [1265](https://leetcode-cn.com/problems/print-immutable-linked-list-in-reverse) | 逆序打印不可变链表 |  | `栈`,`递归`,`链表`,`双指针` | 中等 | 🔒 |  |
| [1266](https://leetcode-cn.com/problems/minimum-time-visiting-all-points) | 访问所有点的最小时间 |  | `几何`,`数组`,`数学` | 简单 |  |  |
| [1267](https://leetcode-cn.com/problems/count-servers-that-communicate) | 统计参与通信的服务器 |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`数组`,`计数`,`矩阵` | 中等 |  |  |
| [1268](https://leetcode-cn.com/problems/search-suggestions-system) | 搜索推荐系统 |  | `字典树`,`数组`,`字符串` | 中等 |  |  |
| [1269](https://leetcode-cn.com/problems/number-of-ways-to-stay-in-the-same-place-after-some-steps) | 停在原地的方案数 |  | `动态规划` | 困难 |  |  |
| [1270](https://leetcode-cn.com/problems/all-people-report-to-the-given-manager) | 向公司CEO汇报工作的所有人 |  | `数据库` | 中等 | 🔒 |  |
| [1271](https://leetcode-cn.com/problems/hexspeak) | 十六进制魔术数字 |  | `数学`,`字符串` | 简单 | 🔒 |  |
| [1272](https://leetcode-cn.com/problems/remove-interval) | 删除区间 |  | `数组` | 中等 | 🔒 |  |
| [1273](https://leetcode-cn.com/problems/delete-tree-nodes) | 删除树节点 |  | `树`,`深度优先搜索`,`广度优先搜索` | 中等 | 🔒 |  |
| [1274](https://leetcode-cn.com/problems/number-of-ships-in-a-rectangle) | 矩形内船只的数目 |  | `数组`,`分治`,`交互` | 困难 | 🔒 |  |
| [1275](https://leetcode-cn.com/problems/find-winner-on-a-tic-tac-toe-game) | 找出井字棋的获胜者 |  | `数组`,`哈希表`,`矩阵`,`模拟` | 简单 |  |  |
| [1276](https://leetcode-cn.com/problems/number-of-burgers-with-no-waste-of-ingredients) | 不浪费原料的汉堡制作方案 |  | `数学` | 中等 |  |  |
| [1277](https://leetcode-cn.com/problems/count-square-submatrices-with-all-ones) | 统计全为 1 的正方形子矩阵 |  | `数组`,`动态规划`,`矩阵` | 中等 |  |  |
| [1278](https://leetcode-cn.com/problems/palindrome-partitioning-iii) | 分割回文串 III |  | `字符串`,`动态规划` | 困难 |  |  |
| [1279](https://leetcode-cn.com/problems/traffic-light-controlled-intersection) | 红绿灯路口 |  | `多线程` | 简单 | 🔒 |  |
| [1280](https://leetcode-cn.com/problems/students-and-examinations) | 学生们参加各科测试的次数 |  | `数据库` | 简单 | 🔒 |  |
| [1281](https://leetcode-cn.com/problems/subtract-the-product-and-sum-of-digits-of-an-integer) | 整数的各位积和之差 |  | `数学` | 简单 |  |  |
| [1282](https://leetcode-cn.com/problems/group-the-people-given-the-group-size-they-belong-to) | 用户分组 |  | `数组`,`哈希表` | 中等 |  |  |
| [1283](https://leetcode-cn.com/problems/find-the-smallest-divisor-given-a-threshold) | 使结果不超过阈值的最小除数 |  | `数组`,`二分查找` | 中等 |  |  |
| [1284](https://leetcode-cn.com/problems/minimum-number-of-flips-to-convert-binary-matrix-to-zero-matrix) | 转化为全零矩阵的最少反转次数 |  | `位运算`,`广度优先搜索`,`数组`,`矩阵` | 困难 |  |  |
| [1285](https://leetcode-cn.com/problems/find-the-start-and-end-number-of-continuous-ranges) | 找到连续区间的开始和结束数字 |  | `数据库` | 中等 | 🔒 |  |
| [1286](https://leetcode-cn.com/problems/iterator-for-combination) | 字母组合迭代器 |  | `设计`,`字符串`,`回溯`,`迭代器` | 中等 |  |  |
| [1287](https://leetcode-cn.com/problems/element-appearing-more-than-25-in-sorted-array) | 有序数组中出现次数超过25%的元素 |  | `数组` | 简单 |  |  |
| [1288](https://leetcode-cn.com/problems/remove-covered-intervals) | 删除被覆盖区间 |  | `数组`,`排序` | 中等 |  |  |
| [1289](https://leetcode-cn.com/problems/minimum-falling-path-sum-ii) | 下降路径最小和 II |  | `数组`,`动态规划`,`矩阵` | 困难 |  |  |
| [1290](https://leetcode-cn.com/problems/convert-binary-number-in-a-linked-list-to-integer) | 二进制链表转整数 |  | `链表`,`数学` | 简单 |  |  |
| [1291](https://leetcode-cn.com/problems/sequential-digits) | 顺次数 |  | `枚举` | 中等 |  |  |
| [1292](https://leetcode-cn.com/problems/maximum-side-length-of-a-square-with-sum-less-than-or-equal-to-threshold) | 元素和小于等于阈值的正方形的最大边长 |  | `数组`,`二分查找`,`矩阵`,`前缀和` | 中等 |  |  |
| [1293](https://leetcode-cn.com/problems/shortest-path-in-a-grid-with-obstacles-elimination) | 网格中的最短路径 |  | `广度优先搜索`,`数组`,`矩阵` | 困难 |  |  |
| [1294](https://leetcode-cn.com/problems/weather-type-in-each-country) | 不同国家的天气类型 |  | `数据库` | 简单 | 🔒 |  |
| [1295](https://leetcode-cn.com/problems/find-numbers-with-even-number-of-digits) | 统计位数为偶数的数字 |  | `数组` | 简单 |  |  |
| [1296](https://leetcode-cn.com/problems/divide-array-in-sets-of-k-consecutive-numbers) | 划分数组为连续数字的集合 |  | `贪心`,`数组`,`哈希表`,`排序` | 中等 |  |  |
| [1297](https://leetcode-cn.com/problems/maximum-number-of-occurrences-of-a-substring) | 子串的最大出现次数 |  | `哈希表`,`字符串`,`滑动窗口` | 中等 |  |  |
| [1298](https://leetcode-cn.com/problems/maximum-candies-you-can-get-from-boxes) | 你能从盒子里获得的最大糖果数 |  | `广度优先搜索`,`数组` | 困难 |  |  |
| [1299](https://leetcode-cn.com/problems/replace-elements-with-greatest-element-on-right-side) | 将每个元素替换为右侧最大元素 |  | `数组` | 简单 |  |  |
| [1300](https://leetcode-cn.com/problems/sum-of-mutated-array-closest-to-target) | 转变数组后最接近目标值的数组和 |  | `数组`,`二分查找`,`排序` | 中等 |  |  |
| [1301](https://leetcode-cn.com/problems/number-of-paths-with-max-score) | 最大得分的路径数目 |  | `数组`,`动态规划`,`矩阵` | 困难 |  |  |
| [1302](https://leetcode-cn.com/problems/deepest-leaves-sum) | 层数最深叶子节点的和 |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉树` | 中等 |  |  |
| [1303](https://leetcode-cn.com/problems/find-the-team-size) | 求团队人数 |  | `数据库` | 简单 | 🔒 |  |
| [1304](https://leetcode-cn.com/problems/find-n-unique-integers-sum-up-to-zero) | 和为零的N个唯一整数 |  | `数组`,`数学` | 简单 |  |  |
| [1305](https://leetcode-cn.com/problems/all-elements-in-two-binary-search-trees) | 两棵二叉搜索树中的所有元素 |  | `树`,`深度优先搜索`,`二叉搜索树`,`二叉树`,`排序` | 中等 |  |  |
| [1306](https://leetcode-cn.com/problems/jump-game-iii) | 跳跃游戏 III |  | `深度优先搜索`,`广度优先搜索`,`数组` | 中等 |  |  |
| [1307](https://leetcode-cn.com/problems/verbal-arithmetic-puzzle) | 口算难题 |  | `数组`,`数学`,`字符串`,`回溯` | 困难 |  |  |
| [1308](https://leetcode-cn.com/problems/running-total-for-different-genders) | 不同性别每日分数总计 |  | `数据库` | 中等 | 🔒 |  |
| [1309](https://leetcode-cn.com/problems/decrypt-string-from-alphabet-to-integer-mapping) | 解码字母到整数映射 |  | `字符串` | 简单 |  |  |
| [1310](https://leetcode-cn.com/problems/xor-queries-of-a-subarray) | 子数组异或查询 |  | `位运算`,`数组`,`前缀和` | 中等 |  |  |
| [1311](https://leetcode-cn.com/problems/get-watched-videos-by-your-friends) | 获取你好友已观看的视频 |  | `广度优先搜索`,`数组`,`哈希表`,`排序` | 中等 |  |  |
| [1312](https://leetcode-cn.com/problems/minimum-insertion-steps-to-make-a-string-palindrome) | 让字符串成为回文串的最少插入次数 |  | `字符串`,`动态规划` | 困难 |  |  |
| [1313](https://leetcode-cn.com/problems/decompress-run-length-encoded-list) | 解压缩编码列表 |  | `数组` | 简单 |  |  |
| [1314](https://leetcode-cn.com/problems/matrix-block-sum) | 矩阵区域和 |  | `数组`,`矩阵`,`前缀和` | 中等 |  |  |
| [1315](https://leetcode-cn.com/problems/sum-of-nodes-with-even-valued-grandparent) | 祖父节点值为偶数的节点和 |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉树` | 中等 |  |  |
| [1316](https://leetcode-cn.com/problems/distinct-echo-substrings) | 不同的循环子字符串 |  | `字典树`,`字符串`,`动态规划`,`滑动窗口`,`哈希函数`,`滚动哈希` | 困难 |  |  |
| [1317](https://leetcode-cn.com/problems/convert-integer-to-the-sum-of-two-no-zero-integers) | 将整数转换为两个无零整数的和 |  | `数学` | 简单 |  |  |
| [1318](https://leetcode-cn.com/problems/minimum-flips-to-make-a-or-b-equal-to-c) | 或运算的最小翻转次数 |  | `位运算` | 中等 |  |  |
| [1319](https://leetcode-cn.com/problems/number-of-operations-to-make-network-connected) | 连通网络的操作次数 |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`图` | 中等 |  |  |
| [1320](https://leetcode-cn.com/problems/minimum-distance-to-type-a-word-using-two-fingers) | 二指输入的的最小距离 |  | `字符串`,`动态规划` | 困难 |  |  |
| [1321](https://leetcode-cn.com/problems/restaurant-growth) | 餐馆营业额变化增长 |  | `数据库` | 中等 | 🔒 |  |
| [1322](https://leetcode-cn.com/problems/ads-performance) | 广告效果 |  | `数据库` | 简单 | 🔒 |  |
| [1323](https://leetcode-cn.com/problems/maximum-69-number) | 6 和 9 组成的最大数字 |  | `贪心`,`数学` | 简单 |  |  |
| [1324](https://leetcode-cn.com/problems/print-words-vertically) | 竖直打印单词 |  | `数组`,`字符串`,`模拟` | 中等 |  |  |
| [1325](https://leetcode-cn.com/problems/delete-leaves-with-a-given-value) | 删除给定值的叶子节点 |  | `树`,`深度优先搜索`,`广度优先搜索`,`哈希表`,`二叉树` | 中等 |  |  |
| [1326](https://leetcode-cn.com/problems/minimum-number-of-taps-to-open-to-water-a-garden) | 灌溉花园的最少水龙头数目 |  | `贪心`,`数组`,`动态规划` | 困难 |  |  |
| [1327](https://leetcode-cn.com/problems/list-the-products-ordered-in-a-period) | 列出指定时间段内所有的下单产品 |  | `数据库` | 简单 | 🔒 |  |
| [1328](https://leetcode-cn.com/problems/break-a-palindrome) | 破坏回文串 |  | `贪心`,`字符串` | 中等 |  |  |
| [1329](https://leetcode-cn.com/problems/sort-the-matrix-diagonally) | 将矩阵按对角线排序 |  | `数组`,`矩阵`,`排序` | 中等 |  |  |
| [1330](https://leetcode-cn.com/problems/reverse-subarray-to-maximize-array-value) | 翻转子数组得到最大的数组值 |  | `贪心`,`数组`,`数学` | 困难 |  |  |
| [1331](https://leetcode-cn.com/problems/rank-transform-of-an-array) | 数组序号转换 |  | `数组`,`哈希表`,`排序` | 简单 |  |  |
| [1332](https://leetcode-cn.com/problems/remove-palindromic-subsequences) | 删除回文子序列 |  | `双指针`,`字符串` | 简单 |  |  |
| [1333](https://leetcode-cn.com/problems/filter-restaurants-by-vegan-friendly-price-and-distance) | 餐厅过滤器 |  | `数组`,`排序` | 中等 |  |  |
| [1334](https://leetcode-cn.com/problems/find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance) | 阈值距离内邻居最少的城市 |  | `图`,`动态规划`,`最短路` | 中等 |  |  |
| [1335](https://leetcode-cn.com/problems/minimum-difficulty-of-a-job-schedule) | 工作计划的最低难度 |  | `数组`,`动态规划` | 困难 |  |  |
| [1336](https://leetcode-cn.com/problems/number-of-transactions-per-visit) | 每次访问的交易次数 |  | `数据库` | 困难 | 🔒 |  |
| [1337](https://leetcode-cn.com/problems/the-k-weakest-rows-in-a-matrix) | 矩阵中战斗力最弱的 K 行 |  | `数组`,`二分查找`,`矩阵`,`排序`,`堆（优先队列）` | 简单 |  |  |
| [1338](https://leetcode-cn.com/problems/reduce-array-size-to-the-half) | 数组大小减半 |  | `贪心`,`数组`,`哈希表`,`排序`,`堆（优先队列）` | 中等 |  |  |
| [1339](https://leetcode-cn.com/problems/maximum-product-of-splitted-binary-tree) | 分裂二叉树的最大乘积 |  | `树`,`深度优先搜索`,`二叉树` | 中等 |  |  |
| [1340](https://leetcode-cn.com/problems/jump-game-v) | 跳跃游戏 V |  | `数组`,`动态规划`,`排序` | 困难 |  |  |
| [1341](https://leetcode-cn.com/problems/movie-rating) | 电影评分 |  | `数据库` | 中等 | 🔒 |  |
| [1342](https://leetcode-cn.com/problems/number-of-steps-to-reduce-a-number-to-zero) | 将数字变成 0 的操作次数 |  | `位运算`,`数学` | 简单 |  |  |
| [1343](https://leetcode-cn.com/problems/number-of-sub-arrays-of-size-k-and-average-greater-than-or-equal-to-threshold) | 大小为 K 且平均值大于等于阈值的子数组数目 |  | `数组`,`滑动窗口` | 中等 |  |  |
| [1344](https://leetcode-cn.com/problems/angle-between-hands-of-a-clock) | 时钟指针的夹角 |  | `数学` | 中等 |  |  |
| [1345](https://leetcode-cn.com/problems/jump-game-iv) | 跳跃游戏 IV |  | `广度优先搜索`,`数组`,`哈希表` | 困难 |  |  |
| [1346](https://leetcode-cn.com/problems/check-if-n-and-its-double-exist) | 检查整数及其两倍数是否存在 |  | `数组`,`哈希表`,`双指针`,`二分查找`,`排序` | 简单 |  |  |
| [1347](https://leetcode-cn.com/problems/minimum-number-of-steps-to-make-two-strings-anagram) | 制造字母异位词的最小步骤数 |  | `哈希表`,`字符串` | 中等 |  |  |
| [1348](https://leetcode-cn.com/problems/tweet-counts-per-frequency) | 推文计数 |  | `设计`,`哈希表`,`二分查找`,`有序集合`,`排序` | 中等 |  |  |
| [1349](https://leetcode-cn.com/problems/maximum-students-taking-exam) | 参加考试的最大学生数 |  | `位运算`,`数组`,`动态规划`,`状态压缩`,`矩阵` | 困难 |  |  |
| [1350](https://leetcode-cn.com/problems/students-with-invalid-departments) | 院系无效的学生 |  | `数据库` | 简单 | 🔒 |  |
| [1351](https://leetcode-cn.com/problems/count-negative-numbers-in-a-sorted-matrix) | 统计有序矩阵中的负数 |  | `数组`,`二分查找`,`矩阵` | 简单 |  |  |
| [1352](https://leetcode-cn.com/problems/product-of-the-last-k-numbers) | 最后 K 个数的乘积 |  | `设计`,`队列`,`数组`,`数学`,`数据流` | 中等 |  |  |
| [1353](https://leetcode-cn.com/problems/maximum-number-of-events-that-can-be-attended) | 最多可以参加的会议数目 |  | `贪心`,`数组`,`堆（优先队列）` | 中等 |  |  |
| [1354](https://leetcode-cn.com/problems/construct-target-array-with-multiple-sums) | 多次求和构造目标数组 |  | `数组`,`堆（优先队列）` | 困难 |  |  |
| [1355](https://leetcode-cn.com/problems/activity-participants) | 活动参与者 |  | `数据库` | 中等 | 🔒 |  |
| [1356](https://leetcode-cn.com/problems/sort-integers-by-the-number-of-1-bits) | 根据数字二进制下 1 的数目排序 |  | `位运算`,`数组`,`计数`,`排序` | 简单 |  |  |
| [1357](https://leetcode-cn.com/problems/apply-discount-every-n-orders) | 每隔 n 个顾客打折 |  | `设计`,`数组`,`哈希表` | 中等 |  |  |
| [1358](https://leetcode-cn.com/problems/number-of-substrings-containing-all-three-characters) | 包含所有三种字符的子字符串数目 |  | `哈希表`,`字符串`,`滑动窗口` | 中等 |  |  |
| [1359](https://leetcode-cn.com/problems/count-all-valid-pickup-and-delivery-options) | 有效的快递序列数目 |  | `数学`,`动态规划`,`组合数学` | 困难 |  |  |
| [1360](https://leetcode-cn.com/problems/number-of-days-between-two-dates) | 日期之间隔几天 |  | `数学`,`字符串` | 简单 |  |  |
| [1361](https://leetcode-cn.com/problems/validate-binary-tree-nodes) | 验证二叉树 |  | `树`,`深度优先搜索`,`广度优先搜索`,`并查集`,`图`,`二叉树` | 中等 |  |  |
| [1362](https://leetcode-cn.com/problems/closest-divisors) | 最接近的因数 |  | `数学` | 中等 |  |  |
| [1363](https://leetcode-cn.com/problems/largest-multiple-of-three) | 形成三的最大倍数 |  | `贪心`,`数组`,`动态规划` | 困难 |  |  |
| [1364](https://leetcode-cn.com/problems/number-of-trusted-contacts-of-a-customer) | 顾客的可信联系人数量 |  | `数据库` | 中等 | 🔒 |  |
| [1365](https://leetcode-cn.com/problems/how-many-numbers-are-smaller-than-the-current-number) | 有多少小于当前数字的数字 |  | `数组`,`哈希表`,`计数`,`排序` | 简单 |  |  |
| [1366](https://leetcode-cn.com/problems/rank-teams-by-votes) | 通过投票对团队排名 |  | `数组`,`哈希表`,`字符串`,`计数`,`排序` | 中等 |  |  |
| [1367](https://leetcode-cn.com/problems/linked-list-in-binary-tree) | 二叉树中的列表 |  | `树`,`深度优先搜索`,`广度优先搜索`,`链表`,`二叉树` | 中等 |  |  |
| [1368](https://leetcode-cn.com/problems/minimum-cost-to-make-at-least-one-valid-path-in-a-grid) | 使网格图至少有一条有效路径的最小代价 |  | `广度优先搜索`,`图`,`数组`,`矩阵`,`最短路`,`堆（优先队列）` | 困难 |  |  |
| [1369](https://leetcode-cn.com/problems/get-the-second-most-recent-activity) | 获取最近第二次的活动 |  | `数据库` | 困难 | 🔒 |  |
| [1370](https://leetcode-cn.com/problems/increasing-decreasing-string) | 上升下降字符串 |  | `哈希表`,`字符串`,`计数` | 简单 |  |  |
| [1371](https://leetcode-cn.com/problems/find-the-longest-substring-containing-vowels-in-even-counts) | 每个元音包含偶数次的最长子字符串 |  | `位运算`,`哈希表`,`字符串`,`前缀和` | 中等 |  |  |
| [1372](https://leetcode-cn.com/problems/longest-zigzag-path-in-a-binary-tree) | 二叉树中的最长交错路径 |  | `树`,`深度优先搜索`,`动态规划`,`二叉树` | 中等 |  |  |
| [1373](https://leetcode-cn.com/problems/maximum-sum-bst-in-binary-tree) | 二叉搜索子树的最大键值和 |  | `树`,`深度优先搜索`,`二叉搜索树`,`动态规划`,`二叉树` | 困难 |  |  |
| [1374](https://leetcode-cn.com/problems/generate-a-string-with-characters-that-have-odd-counts) | 生成每种字符都是奇数个的字符串 |  | `字符串` | 简单 |  |  |
| [1375](https://leetcode-cn.com/problems/bulb-switcher-iii) | 灯泡开关 III |  | `数组` | 中等 |  |  |
| [1376](https://leetcode-cn.com/problems/time-needed-to-inform-all-employees) | 通知所有员工所需的时间 |  | `树`,`深度优先搜索`,`广度优先搜索` | 中等 |  |  |
| [1377](https://leetcode-cn.com/problems/frog-position-after-t-seconds) | T 秒后青蛙的位置 |  | `树`,`深度优先搜索`,`广度优先搜索`,`图` | 困难 |  |  |
| [1378](https://leetcode-cn.com/problems/replace-employee-id-with-the-unique-identifier) | 使用唯一标识码替换员工ID |  | `数据库` | 简单 | 🔒 |  |
| [1379](https://leetcode-cn.com/problems/find-a-corresponding-node-of-a-binary-tree-in-a-clone-of-that-tree) | 找出克隆二叉树中的相同节点 |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉树` | 中等 |  |  |
| [1380](https://leetcode-cn.com/problems/lucky-numbers-in-a-matrix) | 矩阵中的幸运数 |  | `数组`,`矩阵` | 简单 |  |  |
| [1381](https://leetcode-cn.com/problems/design-a-stack-with-increment-operation) | 设计一个支持增量操作的栈 |  | `栈`,`设计`,`数组` | 中等 |  |  |
| [1382](https://leetcode-cn.com/problems/balance-a-binary-search-tree) | 将二叉搜索树变平衡 |  | `贪心`,`树`,`深度优先搜索`,`二叉搜索树`,`分治`,`二叉树` | 中等 |  |  |
| [1383](https://leetcode-cn.com/problems/maximum-performance-of-a-team) | 最大的团队表现值 |  | `贪心`,`数组`,`排序`,`堆（优先队列）` | 困难 |  |  |
| [1384](https://leetcode-cn.com/problems/total-sales-amount-by-year) | 按年度列出销售总额 |  | `数据库` | 困难 | 🔒 |  |
| [1385](https://leetcode-cn.com/problems/find-the-distance-value-between-two-arrays) | 两个数组间的距离值 |  | `数组`,`双指针`,`二分查找`,`排序` | 简单 |  |  |
| [1386](https://leetcode-cn.com/problems/cinema-seat-allocation) | 安排电影院座位 |  | `贪心`,`位运算`,`数组`,`哈希表` | 中等 |  |  |
| [1387](https://leetcode-cn.com/problems/sort-integers-by-the-power-value) | 将整数按权重排序 |  | `记忆化搜索`,`动态规划`,`排序` | 中等 |  |  |
| [1388](https://leetcode-cn.com/problems/pizza-with-3n-slices) | 3n 块披萨 |  | `贪心`,`数组`,`动态规划`,`堆（优先队列）` | 困难 |  |  |
| [1389](https://leetcode-cn.com/problems/create-target-array-in-the-given-order) | 按既定顺序创建目标数组 |  | `数组`,`模拟` | 简单 |  |  |
| [1390](https://leetcode-cn.com/problems/four-divisors) | 四因数 |  | `数组`,`数学` | 中等 |  |  |
| [1391](https://leetcode-cn.com/problems/check-if-there-is-a-valid-path-in-a-grid) | 检查网格中是否存在有效路径 |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`数组`,`矩阵` | 中等 |  |  |
| [1392](https://leetcode-cn.com/problems/longest-happy-prefix) | 最长快乐前缀 |  | `字符串`,`字符串匹配`,`哈希函数`,`滚动哈希` | 困难 |  |  |
| [1393](https://leetcode-cn.com/problems/capital-gainloss) | 股票的资本损益 |  | `数据库` | 中等 | 🔒 |  |
| [1394](https://leetcode-cn.com/problems/find-lucky-integer-in-an-array) | 找出数组中的幸运数 |  | `数组`,`哈希表`,`计数` | 简单 |  |  |
| [1395](https://leetcode-cn.com/problems/count-number-of-teams) | 统计作战单位数 |  | `树状数组`,`数组`,`动态规划` | 中等 |  |  |
| [1396](https://leetcode-cn.com/problems/design-underground-system) | 设计地铁系统 |  | `设计`,`哈希表`,`字符串` | 中等 |  |  |
| [1397](https://leetcode-cn.com/problems/find-all-good-strings) | 找到所有好字符串 |  | `字符串`,`动态规划`,`字符串匹配` | 困难 |  |  |
| [1398](https://leetcode-cn.com/problems/customers-who-bought-products-a-and-b-but-not-c) | 购买了产品 A 和产品 B 却没有购买产品 C 的顾客 |  | `数据库` | 中等 | 🔒 |  |
| [1399](https://leetcode-cn.com/problems/count-largest-group) | 统计最大组的数目 |  | `哈希表`,`数学` | 简单 |  |  |
| [1400](https://leetcode-cn.com/problems/construct-k-palindrome-strings) | 构造 K 个回文字符串 |  | `贪心`,`哈希表`,`字符串`,`计数` | 中等 |  |  |
| [1401](https://leetcode-cn.com/problems/circle-and-rectangle-overlapping) | 圆和矩形是否有重叠 |  | `几何`,`数学` | 中等 |  |  |
| [1402](https://leetcode-cn.com/problems/reducing-dishes) | 做菜顺序 |  | `贪心`,`数组`,`动态规划`,`排序` | 困难 |  |  |
| [1403](https://leetcode-cn.com/problems/minimum-subsequence-in-non-increasing-order) | 非递增顺序的最小子序列 |  | `贪心`,`数组`,`排序` | 简单 |  |  |
| [1404](https://leetcode-cn.com/problems/number-of-steps-to-reduce-a-number-in-binary-representation-to-one) | 将二进制表示减到 1 的步骤数 |  | `位运算`,`字符串` | 中等 |  |  |
| [1405](https://leetcode-cn.com/problems/longest-happy-string) | 最长快乐字符串 |  | `贪心`,`字符串`,`堆（优先队列）` | 中等 |  |  |
| [1406](https://leetcode-cn.com/problems/stone-game-iii) | 石子游戏 III |  | `数组`,`数学`,`动态规划`,`博弈` | 困难 |  |  |
| [1407](https://leetcode-cn.com/problems/top-travellers) | 排名靠前的旅行者 |  | `数据库` | 简单 | 🔒 |  |
| [1408](https://leetcode-cn.com/problems/string-matching-in-an-array) | 数组中的字符串匹配 |  | `字符串`,`字符串匹配` | 简单 |  |  |
| [1409](https://leetcode-cn.com/problems/queries-on-a-permutation-with-key) | 查询带键的排列 |  | `树状数组`,`数组`,`模拟` | 中等 |  |  |
| [1410](https://leetcode-cn.com/problems/html-entity-parser) | HTML 实体解析器 |  | `哈希表`,`字符串` | 中等 |  |  |
| [1411](https://leetcode-cn.com/problems/number-of-ways-to-paint-n-3-grid) | 给 N x 3 网格图涂色的方案数 |  | `动态规划` | 困难 |  |  |
| [1412](https://leetcode-cn.com/problems/find-the-quiet-students-in-all-exams) | 查找成绩处于中游的学生 |  | `数据库` | 困难 | 🔒 |  |
| [1413](https://leetcode-cn.com/problems/minimum-value-to-get-positive-step-by-step-sum) | 逐步求和得到正数的最小值 |  | `数组`,`前缀和` | 简单 |  |  |
| [1414](https://leetcode-cn.com/problems/find-the-minimum-number-of-fibonacci-numbers-whose-sum-is-k) | 和为 K 的最少斐波那契数字数目 |  | `贪心` | 中等 |  |  |
| [1415](https://leetcode-cn.com/problems/the-k-th-lexicographical-string-of-all-happy-strings-of-length-n) | 长度为 n 的开心字符串中字典序第 k 小的字符串 |  | `字符串`,`回溯` | 中等 |  |  |
| [1416](https://leetcode-cn.com/problems/restore-the-array) | 恢复数组 |  | `字符串`,`动态规划` | 困难 |  |  |
| [1417](https://leetcode-cn.com/problems/reformat-the-string) | 重新格式化字符串 |  | `字符串` | 简单 |  |  |
| [1418](https://leetcode-cn.com/problems/display-table-of-food-orders-in-a-restaurant) | 点菜展示表 |  | `数组`,`哈希表`,`字符串`,`有序集合`,`排序` | 中等 |  |  |
| [1419](https://leetcode-cn.com/problems/minimum-number-of-frogs-croaking) | 数青蛙 |  | `字符串`,`计数` | 中等 |  |  |
| [1420](https://leetcode-cn.com/problems/build-array-where-you-can-find-the-maximum-exactly-k-comparisons) | 生成数组 |  | `动态规划` | 困难 |  |  |
| [1421](https://leetcode-cn.com/problems/npv-queries) | 净现值查询 |  | `数据库` | 中等 | 🔒 |  |
| [1422](https://leetcode-cn.com/problems/maximum-score-after-splitting-a-string) | 分割字符串的最大得分 |  | `字符串` | 简单 |  |  |
| [1423](https://leetcode-cn.com/problems/maximum-points-you-can-obtain-from-cards) | 可获得的最大点数 |  | `数组`,`前缀和`,`滑动窗口` | 中等 |  |  |
| [1424](https://leetcode-cn.com/problems/diagonal-traverse-ii) | 对角线遍历 II |  | `数组`,`排序`,`堆（优先队列）` | 中等 |  |  |
| [1425](https://leetcode-cn.com/problems/constrained-subsequence-sum) | 带限制的子序列和 |  | `队列`,`数组`,`动态规划`,`滑动窗口`,`单调队列`,`堆（优先队列）` | 困难 |  |  |
| [1426](https://leetcode-cn.com/problems/counting-elements) | 数元素 |  | `数组`,`哈希表` | 简单 | 🔒 |  |
| [1427](https://leetcode-cn.com/problems/perform-string-shifts) | 字符串的左右移 |  | `数组`,`数学`,`字符串` | 简单 | 🔒 |  |
| [1428](https://leetcode-cn.com/problems/leftmost-column-with-at-least-a-one) | 至少有一个 1 的最左端列 |  | `数组`,`二分查找`,`交互`,`矩阵` | 中等 | 🔒 |  |
| [1429](https://leetcode-cn.com/problems/first-unique-number) | 第一个唯一数字 |  | `设计`,`队列`,`数组`,`哈希表`,`数据流` | 中等 | 🔒 |  |
| [1430](https://leetcode-cn.com/problems/check-if-a-string-is-a-valid-sequence-from-root-to-leaves-path-in-a-binary-tree) | 判断给定的序列是否是二叉树从根到叶的路径 |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉树` | 中等 | 🔒 |  |
| [1431](https://leetcode-cn.com/problems/kids-with-the-greatest-number-of-candies) | 拥有最多糖果的孩子 |  | `数组` | 简单 |  |  |
| [1432](https://leetcode-cn.com/problems/max-difference-you-can-get-from-changing-an-integer) | 改变一个整数能得到的最大差值 |  | `贪心`,`数学` | 中等 |  |  |
| [1433](https://leetcode-cn.com/problems/check-if-a-string-can-break-another-string) | 检查一个字符串是否可以打破另一个字符串 |  | `贪心`,`字符串`,`排序` | 中等 |  |  |
| [1434](https://leetcode-cn.com/problems/number-of-ways-to-wear-different-hats-to-each-other) | 每个人戴不同帽子的方案数 |  | `位运算`,`数组`,`动态规划`,`状态压缩` | 困难 |  |  |
| [1435](https://leetcode-cn.com/problems/create-a-session-bar-chart) | 制作会话柱状图 |  | `数据库` | 简单 | 🔒 |  |
| [1436](https://leetcode-cn.com/problems/destination-city) | 旅行终点站 |  | `哈希表`,`字符串` | 简单 |  |  |
| [1437](https://leetcode-cn.com/problems/check-if-all-1s-are-at-least-length-k-places-away) | 是否所有 1 都至少相隔 k 个元素 |  | `数组` | 简单 |  |  |
| [1438](https://leetcode-cn.com/problems/longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit) | 绝对差不超过限制的最长连续子数组 |  | `队列`,`数组`,`有序集合`,`滑动窗口`,`单调队列`,`堆（优先队列）` | 中等 |  |  |
| [1439](https://leetcode-cn.com/problems/find-the-kth-smallest-sum-of-a-matrix-with-sorted-rows) | 有序矩阵中的第 k 个最小数组和 |  | `数组`,`二分查找`,`矩阵`,`堆（优先队列）` | 困难 |  |  |
| [1440](https://leetcode-cn.com/problems/evaluate-boolean-expression) | 计算布尔表达式的值 |  | `数据库` | 中等 | 🔒 |  |
| [1441](https://leetcode-cn.com/problems/build-an-array-with-stack-operations) | 用栈操作构建数组 |  | `栈`,`数组`,`模拟` | 简单 |  |  |
| [1442](https://leetcode-cn.com/problems/count-triplets-that-can-form-two-arrays-of-equal-xor) | 形成两个异或相等数组的三元组数目 |  | `位运算`,`数组`,`哈希表`,`数学`,`前缀和` | 中等 |  |  |
| [1443](https://leetcode-cn.com/problems/minimum-time-to-collect-all-apples-in-a-tree) | 收集树上所有苹果的最少时间 |  | `树`,`深度优先搜索`,`广度优先搜索`,`哈希表` | 中等 |  |  |
| [1444](https://leetcode-cn.com/problems/number-of-ways-of-cutting-a-pizza) | 切披萨的方案数 |  | `记忆化搜索`,`数组`,`动态规划`,`矩阵` | 困难 |  |  |
| [1445](https://leetcode-cn.com/problems/apples-oranges) | 苹果和桔子 |  | `数据库` | 中等 | 🔒 |  |
| [1446](https://leetcode-cn.com/problems/consecutive-characters) | 连续字符 |  | `字符串` | 简单 |  |  |
| [1447](https://leetcode-cn.com/problems/simplified-fractions) | 最简分数 |  | `数学` | 中等 |  |  |
| [1448](https://leetcode-cn.com/problems/count-good-nodes-in-binary-tree) | 统计二叉树中好节点的数目 |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉树` | 中等 |  |  |
| [1449](https://leetcode-cn.com/problems/form-largest-integer-with-digits-that-add-up-to-target) | 数位成本和为目标值的最大数字 |  | `数组`,`动态规划` | 困难 |  |  |
| [1450](https://leetcode-cn.com/problems/number-of-students-doing-homework-at-a-given-time) | 在既定时间做作业的学生人数 |  | `数组` | 简单 |  |  |
| [1451](https://leetcode-cn.com/problems/rearrange-words-in-a-sentence) | 重新排列句子中的单词 |  | `字符串`,`排序` | 中等 |  |  |
| [1452](https://leetcode-cn.com/problems/people-whose-list-of-favorite-companies-is-not-a-subset-of-another-list) | 收藏清单 |  | `数组`,`哈希表`,`字符串` | 中等 |  |  |
| [1453](https://leetcode-cn.com/problems/maximum-number-of-darts-inside-of-a-circular-dartboard) | 圆形靶内的最大飞镖数量 |  | `几何`,`数组`,`数学` | 困难 |  |  |
| [1454](https://leetcode-cn.com/problems/active-users) | 活跃用户 |  | `数据库` | 中等 | 🔒 |  |
| [1455](https://leetcode-cn.com/problems/check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence) | 检查单词是否为句中其他单词的前缀 |  | `字符串`,`字符串匹配` | 简单 |  |  |
| [1456](https://leetcode-cn.com/problems/maximum-number-of-vowels-in-a-substring-of-given-length) | 定长子串中元音的最大数目 |  | `字符串`,`滑动窗口` | 中等 |  |  |
| [1457](https://leetcode-cn.com/problems/pseudo-palindromic-paths-in-a-binary-tree) | 二叉树中的伪回文路径 |  | `位运算`,`树`,`深度优先搜索`,`广度优先搜索`,`二叉树` | 中等 |  |  |
| [1458](https://leetcode-cn.com/problems/max-dot-product-of-two-subsequences) | 两个子序列的最大点积 |  | `数组`,`动态规划` | 困难 |  |  |
| [1459](https://leetcode-cn.com/problems/rectangles-area) | 矩形面积 |  | `数据库` | 中等 | 🔒 |  |
| [1460](https://leetcode-cn.com/problems/make-two-arrays-equal-by-reversing-sub-arrays) | 通过翻转子数组使两个数组相等 |  | `数组`,`哈希表`,`排序` | 简单 |  |  |
| [1461](https://leetcode-cn.com/problems/check-if-a-string-contains-all-binary-codes-of-size-k) | 检查一个字符串是否包含所有长度为 K 的二进制子串 |  | `位运算`,`哈希表`,`字符串`,`哈希函数`,`滚动哈希` | 中等 |  |  |
| [1462](https://leetcode-cn.com/problems/course-schedule-iv) | 课程表 IV |  | `深度优先搜索`,`广度优先搜索`,`图`,`拓扑排序` | 中等 |  |  |
| [1463](https://leetcode-cn.com/problems/cherry-pickup-ii) | 摘樱桃 II |  | `数组`,`动态规划`,`矩阵` | 困难 |  |  |
| [1464](https://leetcode-cn.com/problems/maximum-product-of-two-elements-in-an-array) | 数组中两元素的最大乘积 |  | `数组`,`排序`,`堆（优先队列）` | 简单 |  |  |
| [1465](https://leetcode-cn.com/problems/maximum-area-of-a-piece-of-cake-after-horizontal-and-vertical-cuts) | 切割后面积最大的蛋糕 |  | `贪心`,`数组`,`排序` | 中等 |  |  |
| [1466](https://leetcode-cn.com/problems/reorder-routes-to-make-all-paths-lead-to-the-city-zero) | 重新规划路线 |  | `深度优先搜索`,`广度优先搜索`,`图` | 中等 |  |  |
| [1467](https://leetcode-cn.com/problems/probability-of-a-two-boxes-having-the-same-number-of-distinct-balls) | 两个盒子中球的颜色数相同的概率 |  | `数学`,`动态规划`,`回溯`,`组合数学`,`概率与统计` | 困难 |  |  |
| [1468](https://leetcode-cn.com/problems/calculate-salaries) | 计算税后工资 |  | `数据库` | 中等 | 🔒 |  |
| [1469](https://leetcode-cn.com/problems/find-all-the-lonely-nodes) | 寻找所有的独生节点 |  | `树`,`深度优先搜索`,`广度优先搜索`,`二叉树` | 简单 | 🔒 |  |
| [1470](https://leetcode-cn.com/problems/shuffle-the-array) | 重新排列数组 |  | `数组` | 简单 |  |  |
| [1471](https://leetcode-cn.com/problems/the-k-strongest-values-in-an-array) | 数组中的 k 个最强值 |  | `数组`,`双指针`,`排序` | 中等 |  |  |
| [1472](https://leetcode-cn.com/problems/design-browser-history) | 设计浏览器历史记录 |  | `栈`,`设计`,`数组`,`链表`,`数据流`,`双向链表` | 中等 |  |  |
| [1473](https://leetcode-cn.com/problems/paint-house-iii) | 粉刷房子 III |  | `数组`,`动态规划` | 困难 |  |  |
| [1474](https://leetcode-cn.com/problems/delete-n-nodes-after-m-nodes-of-a-linked-list) | 删除链表 M 个节点之后的 N 个节点 |  | `链表` | 简单 | 🔒 |  |
| [1475](https://leetcode-cn.com/problems/final-prices-with-a-special-discount-in-a-shop) | 商品折扣后的最终价格 |  | `栈`,`数组`,`单调栈` | 简单 |  |  |
| [1476](https://leetcode-cn.com/problems/subrectangle-queries) | 子矩形查询 |  | `设计`,`数组`,`矩阵` | 中等 |  |  |
| [1477](https://leetcode-cn.com/problems/find-two-non-overlapping-sub-arrays-each-with-target-sum) | 找两个和为目标值且不重叠的子数组 |  | `数组`,`哈希表`,`二分查找`,`动态规划`,`滑动窗口` | 中等 |  |  |
| [1478](https://leetcode-cn.com/problems/allocate-mailboxes) | 安排邮筒 |  | `数组`,`数学`,`动态规划`,`排序` | 困难 |  |  |
| [1479](https://leetcode-cn.com/problems/sales-by-day-of-the-week) | 周内每天的销售情况 |  | `数据库` | 困难 | 🔒 |  |
| [1480](https://leetcode-cn.com/problems/running-sum-of-1d-array) | 一维数组的动态和 |  | `数组`,`前缀和` | 简单 |  |  |
| [1481](https://leetcode-cn.com/problems/least-number-of-unique-integers-after-k-removals) | 不同整数的最少数目 |  | `贪心`,`数组`,`哈希表`,`计数`,`排序` | 中等 |  |  |
| [1482](https://leetcode-cn.com/problems/minimum-number-of-days-to-make-m-bouquets) | 制作 m 束花所需的最少天数 |  | `数组`,`二分查找` | 中等 |  |  |
| [1483](https://leetcode-cn.com/problems/kth-ancestor-of-a-tree-node) | 树节点的第 K 个祖先 |  | `树`,`深度优先搜索`,`广度优先搜索`,`设计`,`二分查找`,`动态规划` | 困难 |  |  |
| [1484](https://leetcode-cn.com/problems/group-sold-products-by-the-date) | 按日期分组销售产品 |  | `数据库` | 简单 | 🔒 |  |
| [1485](https://leetcode-cn.com/problems/clone-binary-tree-with-random-pointer) | 克隆含随机指针的二叉树 |  | `树`,`深度优先搜索`,`广度优先搜索`,`哈希表`,`二叉树` | 中等 | 🔒 |  |
| [1486](https://leetcode-cn.com/problems/xor-operation-in-an-array) | 数组异或操作 |  | `位运算`,`数学` | 简单 |  |  |
| [1487](https://leetcode-cn.com/problems/making-file-names-unique) | 保证文件名唯一 |  | `数组`,`哈希表`,`字符串` | 中等 |  |  |
| [1488](https://leetcode-cn.com/problems/avoid-flood-in-the-city) | 避免洪水泛滥 |  | `贪心`,`数组`,`哈希表`,`二分查找`,`堆（优先队列）` | 中等 |  |  |
| [1489](https://leetcode-cn.com/problems/find-critical-and-pseudo-critical-edges-in-minimum-spanning-tree) | 找到最小生成树里的关键边和伪关键边 |  | `并查集`,`图`,`最小生成树`,`排序`,`强连通分量` | 困难 |  |  |
| [1490](https://leetcode-cn.com/problems/clone-n-ary-tree) | 克隆 N 叉树 |  | `树`,`深度优先搜索`,`广度优先搜索`,`哈希表` | 中等 | 🔒 |  |
| [1491](https://leetcode-cn.com/problems/average-salary-excluding-the-minimum-and-maximum-salary) | 去掉最低工资和最高工资后的工资平均值 |  | `数组`,`排序` | 简单 |  |  |
| [1492](https://leetcode-cn.com/problems/the-kth-factor-of-n) | n 的第 k 个因子 |  | `数学` | 中等 |  |  |
| [1493](https://leetcode-cn.com/problems/longest-subarray-of-1s-after-deleting-one-element) | 删掉一个元素以后全为 1 的最长子数组 |  | `数学`,`动态规划`,`滑动窗口` | 中等 |  |  |
| [1494](https://leetcode-cn.com/problems/parallel-courses-ii) | 并行课程 II |  | `位运算`,`图`,`动态规划`,`状态压缩` | 困难 |  |  |
| [1495](https://leetcode-cn.com/problems/friendly-movies-streamed-last-month) | 上月播放的儿童适宜电影 |  | `数据库` | 简单 | 🔒 |  |
| [1496](https://leetcode-cn.com/problems/path-crossing) | 判断路径是否相交 |  | `哈希表`,`字符串` | 简单 |  |  |
| [1497](https://leetcode-cn.com/problems/check-if-array-pairs-are-divisible-by-k) | 检查数组对是否可以被 k 整除 |  | `数组`,`哈希表`,`计数` | 中等 |  |  |
| [1498](https://leetcode-cn.com/problems/number-of-subsequences-that-satisfy-the-given-sum-condition) | 满足条件的子序列数目 |  | `数组`,`双指针`,`二分查找`,`排序` | 中等 |  |  |
| [1499](https://leetcode-cn.com/problems/max-value-of-equation) | 满足不等式的最大值 |  | `队列`,`数组`,`滑动窗口`,`单调队列`,`堆（优先队列）` | 困难 |  |  |
| [1500](https://leetcode-cn.com/problems/design-a-file-sharing-system) | 设计文件分享系统 |  | `设计`,`哈希表`,`数据流`,`堆（优先队列）` | 中等 | 🔒 |  |
| [1501](https://leetcode-cn.com/problems/countries-you-can-safely-invest-in) | 可以放心投资的国家 |  | `数据库` | 中等 | 🔒 |  |
| [1502](https://leetcode-cn.com/problems/can-make-arithmetic-progression-from-sequence) | 判断能否形成等差数列 |  | `数组`,`排序` | 简单 |  |  |
| [1503](https://leetcode-cn.com/problems/last-moment-before-all-ants-fall-out-of-a-plank) | 所有蚂蚁掉下来前的最后一刻 |  | `脑筋急转弯`,`数组`,`模拟` | 中等 |  |  |
| [1504](https://leetcode-cn.com/problems/count-submatrices-with-all-ones) | 统计全 1 子矩形 |  | `栈`,`数组`,`动态规划`,`矩阵`,`单调栈` | 中等 |  |  |
| [1505](https://leetcode-cn.com/problems/minimum-possible-integer-after-at-most-k-adjacent-swaps-on-digits) | 最多 K 次交换相邻数位后得到的最小整数 |  | `贪心`,`树状数组`,`线段树`,`字符串` | 困难 |  |  |
| [1506](https://leetcode-cn.com/problems/find-root-of-n-ary-tree) | 找到 N 叉树的根节点 |  | `位运算`,`树`,`深度优先搜索`,`哈希表` | 中等 | 🔒 |  |
| [1507](https://leetcode-cn.com/problems/reformat-date) | 转变日期格式 |  | `字符串` | 简单 |  |  |
| [1508](https://leetcode-cn.com/problems/range-sum-of-sorted-subarray-sums) | 子数组和排序后的区间和 |  | `数组`,`双指针`,`二分查找`,`排序` | 中等 |  |  |
| [1509](https://leetcode-cn.com/problems/minimum-difference-between-largest-and-smallest-value-in-three-moves) | 三次操作后最大值与最小值的最小差 |  | `贪心`,`数组`,`排序` | 中等 |  |  |
| [1510](https://leetcode-cn.com/problems/stone-game-iv) | 石子游戏 IV |  | `数学`,`动态规划`,`博弈` | 困难 |  |  |
| [1511](https://leetcode-cn.com/problems/customer-order-frequency) | 消费者下单频率 |  | `数据库` | 简单 | 🔒 |  |
| [1512](https://leetcode-cn.com/problems/number-of-good-pairs) | 好数对的数目 |  | `数组`,`哈希表`,`数学`,`计数` | 简单 |  |  |
| [1513](https://leetcode-cn.com/problems/number-of-substrings-with-only-1s) | 仅含 1 的子串数 |  | `数学`,`字符串` | 中等 |  |  |
| [1514](https://leetcode-cn.com/problems/path-with-maximum-probability) | 概率最大的路径 |  | `图`,`最短路`,`堆（优先队列）` | 中等 |  |  |
| [1515](https://leetcode-cn.com/problems/best-position-for-a-service-centre) | 服务中心的最佳位置 |  | `几何`,`数学`,`随机化` | 困难 |  |  |
| [1516](https://leetcode-cn.com/problems/move-sub-tree-of-n-ary-tree) | 移动 N 叉树的子树 |  | `树`,`深度优先搜索` | 困难 | 🔒 |  |
| [1517](https://leetcode-cn.com/problems/find-users-with-valid-e-mails) | 查找拥有有效邮箱的用户 |  | `数据库` | 简单 | 🔒 |  |
| [1518](https://leetcode-cn.com/problems/water-bottles) | 换酒问题 |  | `数学`,`模拟` | 简单 |  |  |
| [1519](https://leetcode-cn.com/problems/number-of-nodes-in-the-sub-tree-with-the-same-label) | 子树中标签相同的节点数 |  | `树`,`深度优先搜索`,`广度优先搜索` | 中等 |  |  |
| [1520](https://leetcode-cn.com/problems/maximum-number-of-non-overlapping-substrings) | 最多的不重叠子字符串 |  | `贪心`,`字符串` | 困难 |  |  |
| [1521](https://leetcode-cn.com/problems/find-a-value-of-a-mysterious-function-closest-to-target) | 找到最接近目标值的函数值 |  | `位运算`,`线段树`,`数组`,`二分查找` | 困难 |  |  |
| [1522](https://leetcode-cn.com/problems/diameter-of-n-ary-tree) | N 叉树的直径 |  | `树`,`深度优先搜索` | 中等 | 🔒 |  |
| [1523](https://leetcode-cn.com/problems/count-odd-numbers-in-an-interval-range) | 在区间范围内统计奇数数目 |  | `数学` | 简单 |  |  |
| [1524](https://leetcode-cn.com/problems/number-of-sub-arrays-with-odd-sum) | 和为奇数的子数组数目 |  | `数组`,`数学`,`动态规划`,`前缀和` | 中等 |  |  |
| [1525](https://leetcode-cn.com/problems/number-of-good-ways-to-split-a-string) | 字符串的好分割数目 |  | `位运算`,`字符串`,`动态规划` | 中等 |  |  |
| [1526](https://leetcode-cn.com/problems/minimum-number-of-increments-on-subarrays-to-form-a-target-array) | 形成目标数组的子数组最少增加次数 |  | `栈`,`贪心`,`数组`,`动态规划`,`单调栈` | 困难 |  |  |
| [1527](https://leetcode-cn.com/problems/patients-with-a-condition) | 患某种疾病的患者 |  | `数据库` | 简单 | 🔒 |  |
| [1528](https://leetcode-cn.com/problems/shuffle-string) | 重新排列字符串 |  | `数组`,`字符串` | 简单 |  |  |
| [1529](https://leetcode-cn.com/problems/bulb-switcher-iv) | 灯泡开关 IV |  | `贪心`,`字符串` | 中等 |  |  |
| [1530](https://leetcode-cn.com/problems/number-of-good-leaf-nodes-pairs) | 好叶子节点对的数量 |  | `树`,`深度优先搜索`,`二叉树` | 中等 |  |  |
| [1531](https://leetcode-cn.com/problems/string-compression-ii) | 压缩字符串 II |  | `字符串`,`动态规划` | 困难 |  |  |
| [1532](https://leetcode-cn.com/problems/the-most-recent-three-orders) | 最近的三笔订单 |  | `数据库` | 中等 | 🔒 |  |
| [1533](https://leetcode-cn.com/problems/find-the-index-of-the-large-integer) | 找到最大整数的索引 |  | `数组`,`二分查找`,`交互` | 中等 | 🔒 |  |
| [1534](https://leetcode-cn.com/problems/count-good-triplets) | 统计好三元组 |  | `数组`,`枚举` | 简单 |  |  |
| [1535](https://leetcode-cn.com/problems/find-the-winner-of-an-array-game) | 找出数组游戏的赢家 |  | `数组`,`模拟` | 中等 |  |  |
| [1536](https://leetcode-cn.com/problems/minimum-swaps-to-arrange-a-binary-grid) | 排布二进制网格的最少交换次数 |  | `贪心`,`数组`,`矩阵` | 中等 |  |  |
| [1537](https://leetcode-cn.com/problems/get-the-maximum-score) | 最大得分 |  | `贪心`,`数组`,`双指针`,`动态规划` | 困难 |  |  |
| [1538](https://leetcode-cn.com/problems/guess-the-majority-in-a-hidden-array) | 找出隐藏数组中出现次数最多的元素 |  | `数组`,`数学`,`交互` | 中等 | 🔒 |  |
| [1539](https://leetcode-cn.com/problems/kth-missing-positive-number) | 第 k 个缺失的正整数 |  | `数组`,`二分查找` | 简单 |  |  |
| [1540](https://leetcode-cn.com/problems/can-convert-string-in-k-moves) | K 次操作转变字符串 |  | `哈希表`,`字符串` | 中等 |  |  |
| [1541](https://leetcode-cn.com/problems/minimum-insertions-to-balance-a-parentheses-string) | 平衡括号字符串的最少插入次数 |  | `栈`,`贪心`,`字符串` | 中等 |  |  |
| [1542](https://leetcode-cn.com/problems/find-longest-awesome-substring) | 找出最长的超赞子字符串 |  | `位运算`,`哈希表`,`字符串` | 困难 |  |  |
| [1543](https://leetcode-cn.com/problems/fix-product-name-format) | 产品名称格式修复 |  | `数据库` | 简单 | 🔒 |  |
| [1544](https://leetcode-cn.com/problems/make-the-string-great) | 整理字符串 |  | `栈`,`字符串` | 简单 |  |  |
| [1545](https://leetcode-cn.com/problems/find-kth-bit-in-nth-binary-string) | 找出第 N 个二进制字符串中的第 K 位 |  | `递归`,`字符串` | 中等 |  |  |
| [1546](https://leetcode-cn.com/problems/maximum-number-of-non-overlapping-subarrays-with-sum-equals-target) | 和为目标值且不重叠的非空子数组的最大数目 |  | `贪心`,`数组`,`哈希表`,`前缀和` | 中等 |  |  |
| [1547](https://leetcode-cn.com/problems/minimum-cost-to-cut-a-stick) | 切棍子的最小成本 |  | `数组`,`动态规划` | 困难 |  |  |
| [1548](https://leetcode-cn.com/problems/the-most-similar-path-in-a-graph) | 图中最相似的路径 |  | `图`,`动态规划` | 困难 | 🔒 |  |
| [1549](https://leetcode-cn.com/problems/the-most-recent-orders-for-each-product) | 每件商品的最新订单 |  | `数据库` | 中等 | 🔒 |  |
| [1550](https://leetcode-cn.com/problems/three-consecutive-odds) | 存在连续三个奇数的数组 |  | `数组` | 简单 |  |  |
| [1551](https://leetcode-cn.com/problems/minimum-operations-to-make-array-equal) | 使数组中所有元素相等的最小操作数 |  | `数学` | 中等 |  |  |
| [1552](https://leetcode-cn.com/problems/magnetic-force-between-two-balls) | 两球之间的磁力 |  | `数组`,`二分查找`,`排序` | 中等 |  |  |
| [1553](https://leetcode-cn.com/problems/minimum-number-of-days-to-eat-n-oranges) | 吃掉 N 个橘子的最少天数 |  | `记忆化搜索`,`动态规划` | 困难 |  |  |
| [1554](https://leetcode-cn.com/problems/strings-differ-by-one-character) | 只有一个不同字符的字符串 |  | `哈希表`,`字符串`,`哈希函数`,`滚动哈希` | 中等 | 🔒 |  |
| [1555](https://leetcode-cn.com/problems/bank-account-summary) | 银行账户概要 |  | `数据库` | 中等 | 🔒 |  |
| [1556](https://leetcode-cn.com/problems/thousand-separator) | 千位分隔数 |  | `字符串` | 简单 |  |  |
| [1557](https://leetcode-cn.com/problems/minimum-number-of-vertices-to-reach-all-nodes) | 可以到达所有点的最少点数目 |  | `图` | 中等 |  |  |
| [1558](https://leetcode-cn.com/problems/minimum-numbers-of-function-calls-to-make-target-array) | 得到目标数组的最少函数调用次数 |  | `贪心`,`数组` | 中等 |  |  |
| [1559](https://leetcode-cn.com/problems/detect-cycles-in-2d-grid) | 二维网格图中探测环 |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`数组`,`矩阵` | 困难 |  |  |
| [1560](https://leetcode-cn.com/problems/most-visited-sector-in-a-circular-track) | 圆形赛道上经过次数最多的扇区 |  | `数组`,`模拟` | 简单 |  |  |
| [1561](https://leetcode-cn.com/problems/maximum-number-of-coins-you-can-get) | 你可以获得的最大硬币数目 |  | `贪心`,`数组`,`数学`,`博弈`,`排序` | 中等 |  |  |
| [1562](https://leetcode-cn.com/problems/find-latest-group-of-size-m) | 查找大小为 M 的最新分组 |  | `数组`,`二分查找`,`模拟` | 中等 |  |  |
| [1563](https://leetcode-cn.com/problems/stone-game-v) | 石子游戏 V |  | `数组`,`数学`,`动态规划`,`博弈` | 困难 |  |  |
| [1564](https://leetcode-cn.com/problems/put-boxes-into-the-warehouse-i) | 把箱子放进仓库里 I |  | `贪心`,`数组`,`排序` | 中等 | 🔒 |  |
| [1565](https://leetcode-cn.com/problems/unique-orders-and-customers-per-month) | 按月统计订单数与顾客数 |  | `数据库` | 简单 | 🔒 |  |
| [1566](https://leetcode-cn.com/problems/detect-pattern-of-length-m-repeated-k-or-more-times) | 重复至少 K 次且长度为 M 的模式 |  | `数组`,`枚举` | 简单 |  |  |
| [1567](https://leetcode-cn.com/problems/maximum-length-of-subarray-with-positive-product) | 乘积为正数的最长子数组长度 |  | `贪心`,`数组`,`动态规划` | 中等 |  |  |
| [1568](https://leetcode-cn.com/problems/minimum-number-of-days-to-disconnect-island) | 使陆地分离的最少天数 |  | `深度优先搜索`,`广度优先搜索`,`数组`,`矩阵`,`强连通分量` | 困难 |  |  |
| [1569](https://leetcode-cn.com/problems/number-of-ways-to-reorder-array-to-get-same-bst) | 将子数组重新排序得到同一个二叉查找树的方案数 |  | `树`,`并查集`,`二叉搜索树`,`记忆化搜索`,`数组`,`数学`,`分治`,`动态规划`,`二叉树`,`组合数学` | 困难 |  |  |
| [1570](https://leetcode-cn.com/problems/dot-product-of-two-sparse-vectors) | 两个稀疏向量的点积 |  | `设计`,`数组`,`哈希表`,`双指针` | 中等 | 🔒 |  |
| [1571](https://leetcode-cn.com/problems/warehouse-manager) | 仓库经理 |  | `数据库` | 简单 | 🔒 |  |
| [1572](https://leetcode-cn.com/problems/matrix-diagonal-sum) | 矩阵对角线元素的和 |  | `数组`,`矩阵` | 简单 |  |  |
| [1573](https://leetcode-cn.com/problems/number-of-ways-to-split-a-string) | 分割字符串的方案数 |  | `数学`,`字符串` | 中等 |  |  |
| [1574](https://leetcode-cn.com/problems/shortest-subarray-to-be-removed-to-make-array-sorted) | 删除最短的子数组使剩余数组有序 |  | `栈`,`数组`,`双指针`,`二分查找`,`单调栈` | 中等 |  |  |
| [1575](https://leetcode-cn.com/problems/count-all-possible-routes) | 统计所有可行路径 |  | `记忆化搜索`,`数组`,`动态规划` | 困难 |  |  |
| [1576](https://leetcode-cn.com/problems/replace-all-s-to-avoid-consecutive-repeating-characters) | 替换所有的问号 |  | `字符串` | 简单 |  |  |
| [1577](https://leetcode-cn.com/problems/number-of-ways-where-square-of-number-is-equal-to-product-of-two-numbers) | 数的平方等于两数乘积的方法数 |  | `数组`,`哈希表`,`数学`,`双指针` | 中等 |  |  |
| [1578](https://leetcode-cn.com/problems/minimum-deletion-cost-to-avoid-repeating-letters) | 避免重复字母的最小删除成本 |  | `贪心`,`数组`,`字符串`,`动态规划` | 中等 |  |  |
| [1579](https://leetcode-cn.com/problems/remove-max-number-of-edges-to-keep-graph-fully-traversable) | 保证图可完全遍历 |  | `并查集`,`图` | 困难 |  |  |
| [1580](https://leetcode-cn.com/problems/put-boxes-into-the-warehouse-ii) | 把箱子放进仓库里 II |  | `贪心`,`数组`,`排序` | 中等 | 🔒 |  |
| [1581](https://leetcode-cn.com/problems/customer-who-visited-but-did-not-make-any-transactions) | 进店却未进行过交易的顾客 |  | `数据库` | 简单 | 🔒 |  |
| [1582](https://leetcode-cn.com/problems/special-positions-in-a-binary-matrix) | 二进制矩阵中的特殊位置 |  | `数组`,`矩阵` | 简单 |  |  |
| [1583](https://leetcode-cn.com/problems/count-unhappy-friends) | 统计不开心的朋友 |  | `数组`,`模拟` | 中等 |  |  |
| [1584](https://leetcode-cn.com/problems/min-cost-to-connect-all-points) | 连接所有点的最小费用 |  | `并查集`,`数组`,`最小生成树` | 中等 |  |  |
| [1585](https://leetcode-cn.com/problems/check-if-string-is-transformable-with-substring-sort-operations) | 检查字符串是否可以通过排序子字符串得到另一个字符串 |  | `贪心`,`字符串`,`排序` | 困难 |  |  |
| [1586](https://leetcode-cn.com/problems/binary-search-tree-iterator-ii) | 二叉搜索树迭代器 II |  | `栈`,`树`,`设计`,`二叉搜索树`,`二叉树`,`迭代器` | 中等 | 🔒 |  |
| [1587](https://leetcode-cn.com/problems/bank-account-summary-ii) | 银行账户概要 II |  | `数据库` | 简单 | 🔒 |  |
| [1588](https://leetcode-cn.com/problems/sum-of-all-odd-length-subarrays) | 所有奇数长度子数组的和 |  | `数组`,`前缀和` | 简单 |  |  |
| [1589](https://leetcode-cn.com/problems/maximum-sum-obtained-of-any-permutation) | 所有排列中的最大和 |  | `贪心`,`数组`,`前缀和`,`排序` | 中等 |  |  |
| [1590](https://leetcode-cn.com/problems/make-sum-divisible-by-p) | 使数组和能被 P 整除 |  | `数组`,`哈希表`,`前缀和` | 中等 |  |  |
| [1591](https://leetcode-cn.com/problems/strange-printer-ii) | 奇怪的打印机 II |  | `图`,`拓扑排序`,`数组`,`矩阵` | 困难 |  |  |
| [1592](https://leetcode-cn.com/problems/rearrange-spaces-between-words) | 重新排列单词间的空格 |  | `字符串` | 简单 |  |  |
| [1593](https://leetcode-cn.com/problems/split-a-string-into-the-max-number-of-unique-substrings) | 拆分字符串使唯一子字符串的数目最大 |  | `哈希表`,`字符串`,`回溯` | 中等 |  |  |
| [1594](https://leetcode-cn.com/problems/maximum-non-negative-product-in-a-matrix) | 矩阵的最大非负积 |  | `数组`,`动态规划`,`矩阵` | 中等 |  |  |
| [1595](https://leetcode-cn.com/problems/minimum-cost-to-connect-two-groups-of-points) | 连通两组点的最小成本 |  | `位运算`,`数组`,`动态规划`,`状态压缩`,`矩阵` | 困难 |  |  |
| [1596](https://leetcode-cn.com/problems/the-most-frequently-ordered-products-for-each-customer) | 每位顾客最经常订购的商品 |  | `数据库` | 中等 | 🔒 |  |
| [1597](https://leetcode-cn.com/problems/build-binary-expression-tree-from-infix-expression) | 根据中缀表达式构造二叉表达式树 |  | `栈`,`树`,`字符串`,`二叉树` | 困难 | 🔒 |  |
| [1598](https://leetcode-cn.com/problems/crawler-log-folder) | 文件夹操作日志搜集器 |  | `栈`,`数组`,`字符串` | 简单 |  |  |
| [1599](https://leetcode-cn.com/problems/maximum-profit-of-operating-a-centennial-wheel) | 经营摩天轮的最大利润 |  | `数组`,`模拟` | 中等 |  |  |
| [1600](https://leetcode-cn.com/problems/throne-inheritance) | 皇位继承顺序 |  | `树`,`深度优先搜索`,`设计`,`哈希表` | 中等 |  |  |
| [1601](https://leetcode-cn.com/problems/maximum-number-of-achievable-transfer-requests) | 最多可达成的换楼请求数目 |  | `位运算`,`枚举` | 困难 |  |  |
| [1602](https://leetcode-cn.com/problems/find-nearest-right-node-in-binary-tree) | 找到二叉树中最近的右侧节点 |  | `树`,`广度优先搜索`,`二叉树` | 中等 | 🔒 |  |
| [1603](https://leetcode-cn.com/problems/design-parking-system) | 设计停车系统 |  | `设计`,`计数`,`模拟` | 简单 |  |  |
| [1604](https://leetcode-cn.com/problems/alert-using-same-key-card-three-or-more-times-in-a-one-hour-period) | 警告一小时内使用相同员工卡大于等于三次的人 |  | `数组`,`哈希表`,`字符串`,`排序` | 中等 |  |  |
| [1605](https://leetcode-cn.com/problems/find-valid-matrix-given-row-and-column-sums) | 给定行和列的和求可行矩阵 |  | `贪心`,`数组`,`矩阵` | 中等 |  |  |
| [1606](https://leetcode-cn.com/problems/find-servers-that-handled-most-number-of-requests) | 找到处理最多请求的服务器 |  | `贪心`,`数组`,`有序集合`,`堆（优先队列）` | 困难 |  |  |
| [1607](https://leetcode-cn.com/problems/sellers-with-no-sales) | 没有卖出的卖家 |  | `数据库` | 简单 | 🔒 |  |
| [1608](https://leetcode-cn.com/problems/special-array-with-x-elements-greater-than-or-equal-x) | 特殊数组的特征值 |  | `数组`,`二分查找`,`排序` | 简单 |  |  |
| [1609](https://leetcode-cn.com/problems/even-odd-tree) | 奇偶树 |  | `树`,`广度优先搜索`,`二叉树` | 中等 |  |  |
| [1610](https://leetcode-cn.com/problems/maximum-number-of-visible-points) | 可见点的最大数目 |  | `几何`,`数组`,`数学`,`排序`,`滑动窗口` | 困难 |  |  |
| [1611](https://leetcode-cn.com/problems/minimum-one-bit-operations-to-make-integers-zero) | 使整数变为 0 的最少操作次数 |  | `位运算`,`记忆化搜索`,`动态规划` | 困难 |  |  |
| [1612](https://leetcode-cn.com/problems/check-if-two-expression-trees-are-equivalent) | 检查两棵二叉表达式树是否等价 |  | `树`,`深度优先搜索`,`二叉树` | 中等 | 🔒 |  |
| [1613](https://leetcode-cn.com/problems/find-the-missing-ids) | 找到遗失的ID |  | `数据库` | 中等 | 🔒 |  |
| [1614](https://leetcode-cn.com/problems/maximum-nesting-depth-of-the-parentheses) | 括号的最大嵌套深度 |  | `栈`,`字符串` | 简单 |  |  |
| [1615](https://leetcode-cn.com/problems/maximal-network-rank) | 最大网络秩 |  | `图` | 中等 |  |  |
| [1616](https://leetcode-cn.com/problems/split-two-strings-to-make-palindrome) | 分割两个字符串得到回文串 |  | `贪心`,`双指针`,`字符串` | 中等 |  |  |
| [1617](https://leetcode-cn.com/problems/count-subtrees-with-max-distance-between-cities) | 统计子树中城市之间最大距离 |  | `位运算`,`树`,`动态规划`,`状态压缩`,`枚举` | 困难 |  |  |
| [1618](https://leetcode-cn.com/problems/maximum-font-to-fit-a-sentence-in-a-screen) | 找出适应屏幕的最大字号 |  | `数组`,`字符串`,`二分查找`,`交互` | 中等 | 🔒 |  |
| [1619](https://leetcode-cn.com/problems/mean-of-array-after-removing-some-elements) | 删除某些元素后的数组均值 |  | `数组`,`排序` | 简单 |  |  |
| [1620](https://leetcode-cn.com/problems/coordinate-with-maximum-network-quality) | 网络信号最好的坐标 |  | `数组`,`枚举` | 中等 |  |  |
| [1621](https://leetcode-cn.com/problems/number-of-sets-of-k-non-overlapping-line-segments) | 大小为 K 的不重叠线段的数目 |  | `数学`,`动态规划` | 中等 |  |  |
| [1622](https://leetcode-cn.com/problems/fancy-sequence) | 奇妙序列 |  | `设计`,`线段树`,`数学` | 困难 |  |  |
| [1623](https://leetcode-cn.com/problems/all-valid-triplets-that-can-represent-a-country) | 三人国家代表队 |  | `数据库` | 简单 | 🔒 |  |
| [1624](https://leetcode-cn.com/problems/largest-substring-between-two-equal-characters) | 两个相同字符之间的最长子字符串 |  | `哈希表`,`字符串` | 简单 |  |  |
| [1625](https://leetcode-cn.com/problems/lexicographically-smallest-string-after-applying-operations) | 执行操作后字典序最小的字符串 |  | `广度优先搜索`,`字符串` | 中等 |  |  |
| [1626](https://leetcode-cn.com/problems/best-team-with-no-conflicts) | 无矛盾的最佳球队 |  | `数组`,`动态规划`,`排序` | 中等 |  |  |
| [1627](https://leetcode-cn.com/problems/graph-connectivity-with-threshold) | 带阈值的图连通性 |  | `并查集`,`数组`,`数学` | 困难 |  |  |
| [1628](https://leetcode-cn.com/problems/design-an-expression-tree-with-evaluate-function) | 设计带解析函数的表达式树 |  | `栈`,`树`,`设计`,`数学`,`二叉树` | 中等 | 🔒 |  |
| [1629](https://leetcode-cn.com/problems/slowest-key) | 按键持续时间最长的键 |  | `数组`,`字符串` | 简单 |  |  |
| [1630](https://leetcode-cn.com/problems/arithmetic-subarrays) | 等差子数组 |  | `数组`,`排序` | 中等 |  |  |
| [1631](https://leetcode-cn.com/problems/path-with-minimum-effort) | 最小体力消耗路径 |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`数组`,`二分查找`,`矩阵`,`堆（优先队列）` | 中等 |  |  |
| [1632](https://leetcode-cn.com/problems/rank-transform-of-a-matrix) | 矩阵转换后的秩 |  | `贪心`,`并查集`,`图`,`拓扑排序`,`数组`,`矩阵` | 困难 |  |  |
| [1633](https://leetcode-cn.com/problems/percentage-of-users-attended-a-contest) | 各赛事的用户注册率 |  | `数据库` | 简单 | 🔒 |  |
| [1634](https://leetcode-cn.com/problems/add-two-polynomials-represented-as-linked-lists) | 求两个多项式链表的和 |  | `链表`,`数学`,`双指针` | 中等 | 🔒 |  |
| [1635](https://leetcode-cn.com/problems/hopper-company-queries-i) | Hopper 公司查询 I |  | `数据库` | 困难 | 🔒 |  |
| [1636](https://leetcode-cn.com/problems/sort-array-by-increasing-frequency) | 按照频率将数组升序排序 |  | `数组`,`哈希表`,`排序` | 简单 |  |  |
| [1637](https://leetcode-cn.com/problems/widest-vertical-area-between-two-points-containing-no-points) | 两点之间不包含任何点的最宽垂直面积 |  | `数组`,`排序` | 中等 |  |  |
| [1638](https://leetcode-cn.com/problems/count-substrings-that-differ-by-one-character) | 统计只差一个字符的子串数目 |  | `哈希表`,`字符串`,`动态规划` | 中等 |  |  |
| [1639](https://leetcode-cn.com/problems/number-of-ways-to-form-a-target-string-given-a-dictionary) | 通过给定词典构造目标字符串的方案数 |  | `数组`,`字符串`,`动态规划` | 困难 |  |  |
| [1640](https://leetcode-cn.com/problems/check-array-formation-through-concatenation) | 能否连接形成数组 |  | `数组`,`哈希表` | 简单 |  |  |
| [1641](https://leetcode-cn.com/problems/count-sorted-vowel-strings) | 统计字典序元音字符串的数目 |  | `动态规划` | 中等 |  |  |
| [1642](https://leetcode-cn.com/problems/furthest-building-you-can-reach) | 可以到达的最远建筑 |  | `贪心`,`数组`,`堆（优先队列）` | 中等 |  |  |
| [1643](https://leetcode-cn.com/problems/kth-smallest-instructions) | 第 K 条最小指令 |  | `数组`,`数学`,`动态规划`,`组合数学` | 困难 |  |  |
| [1644](https://leetcode-cn.com/problems/lowest-common-ancestor-of-a-binary-tree-ii) | 二叉树的最近公共祖先 II |  | `树`,`深度优先搜索`,`二叉树` | 中等 | 🔒 |  |
| [1645](https://leetcode-cn.com/problems/hopper-company-queries-ii) | Hopper Company Queries II |  | `数据库` | 困难 | 🔒 |  |
| [1646](https://leetcode-cn.com/problems/get-maximum-in-generated-array) | 获取生成数组中的最大值 |  | `数组`,`动态规划`,`模拟` | 简单 |  |  |
| [1647](https://leetcode-cn.com/problems/minimum-deletions-to-make-character-frequencies-unique) | 字符频次唯一的最小删除次数 |  | `贪心`,`字符串`,`排序` | 中等 |  |  |
| [1648](https://leetcode-cn.com/problems/sell-diminishing-valued-colored-balls) | 销售价值减少的颜色球 |  | `贪心`,`数组`,`数学`,`二分查找`,`排序`,`堆（优先队列）` | 中等 |  |  |
| [1649](https://leetcode-cn.com/problems/create-sorted-array-through-instructions) | 通过指令创建有序数组 |  | `树状数组`,`线段树`,`数组`,`二分查找`,`分治`,`有序集合`,`归并排序` | 困难 |  |  |
| [1650](https://leetcode-cn.com/problems/lowest-common-ancestor-of-a-binary-tree-iii) | 二叉树的最近公共祖先 III |  | `树`,`哈希表`,`二叉树` | 中等 | 🔒 |  |
| [1651](https://leetcode-cn.com/problems/hopper-company-queries-iii) | Hopper Company Queries III |  | `数据库` | 困难 | 🔒 |  |
| [1652](https://leetcode-cn.com/problems/defuse-the-bomb) | 拆炸弹 |  | `数组` | 简单 |  |  |
| [1653](https://leetcode-cn.com/problems/minimum-deletions-to-make-string-balanced) | 使字符串平衡的最少删除次数 |  | `栈`,`字符串`,`动态规划` | 中等 |  |  |
| [1654](https://leetcode-cn.com/problems/minimum-jumps-to-reach-home) | 到家的最少跳跃次数 |  | `广度优先搜索`,`数组`,`动态规划` | 中等 |  |  |
| [1655](https://leetcode-cn.com/problems/distribute-repeating-integers) | 分配重复整数 |  | `位运算`,`数组`,`动态规划`,`回溯`,`状态压缩` | 困难 |  |  |
| [1656](https://leetcode-cn.com/problems/design-an-ordered-stream) | 设计有序流 |  | `设计`,`数组`,`哈希表`,`数据流` | 简单 |  |  |
| [1657](https://leetcode-cn.com/problems/determine-if-two-strings-are-close) | 确定两个字符串是否接近 |  | `哈希表`,`字符串`,`排序` | 中等 |  |  |
| [1658](https://leetcode-cn.com/problems/minimum-operations-to-reduce-x-to-zero) | 将 x 减到 0 的最小操作数 |  | `数组`,`哈希表`,`双指针`,`二分查找`,`前缀和` | 中等 |  |  |
| [1659](https://leetcode-cn.com/problems/maximize-grid-happiness) | 最大化网格幸福感 |  | `位运算`,`记忆化搜索`,`动态规划`,`状态压缩` | 困难 |  |  |
| [1660](https://leetcode-cn.com/problems/correct-a-binary-tree) | 纠正二叉树 |  | `树`,`深度优先搜索`,`广度优先搜索`,`哈希表`,`二叉树` | 中等 | 🔒 |  |
| [1661](https://leetcode-cn.com/problems/average-time-of-process-per-machine) | 每台机器的进程平均运行时间 |  | `数据库` | 简单 | 🔒 |  |
| [1662](https://leetcode-cn.com/problems/check-if-two-string-arrays-are-equivalent) | 检查两个字符串数组是否相等 |  | `数组`,`字符串` | 简单 |  |  |
| [1663](https://leetcode-cn.com/problems/smallest-string-with-a-given-numeric-value) | 具有给定数值的最小字符串 |  | `贪心`,`字符串` | 中等 |  |  |
| [1664](https://leetcode-cn.com/problems/ways-to-make-a-fair-array) | 生成平衡数组的方案数 |  | `数组`,`动态规划` | 中等 |  |  |
| [1665](https://leetcode-cn.com/problems/minimum-initial-energy-to-finish-tasks) | 完成所有任务的最少初始能量 |  | `贪心`,`数组`,`排序` | 困难 |  |  |
| [1666](https://leetcode-cn.com/problems/change-the-root-of-a-binary-tree) | 改变二叉树的根节点 |  | `树`,`深度优先搜索`,`二叉树` | 中等 | 🔒 |  |
| [1667](https://leetcode-cn.com/problems/fix-names-in-a-table) | 修复表中的名字 |  | `数据库` | 简单 | 🔒 |  |
| [1668](https://leetcode-cn.com/problems/maximum-repeating-substring) | 最大重复子字符串 |  | `字符串`,`字符串匹配` | 简单 |  |  |
| [1669](https://leetcode-cn.com/problems/merge-in-between-linked-lists) | 合并两个链表 |  | `链表` | 中等 |  |  |
| [1670](https://leetcode-cn.com/problems/design-front-middle-back-queue) | 设计前中后队列 |  | `设计`,`队列`,`数组`,`链表`,`数据流` | 中等 |  |  |
| [1671](https://leetcode-cn.com/problems/minimum-number-of-removals-to-make-mountain-array) | 得到山形数组的最少删除次数 |  | `贪心`,`数组`,`二分查找`,`动态规划` | 困难 |  |  |
| [1672](https://leetcode-cn.com/problems/richest-customer-wealth) | 最富有客户的资产总量 |  | `数组`,`矩阵` | 简单 |  |  |
| [1673](https://leetcode-cn.com/problems/find-the-most-competitive-subsequence) | 找出最具竞争力的子序列 |  | `栈`,`贪心`,`数组`,`单调栈` | 中等 |  |  |
| [1674](https://leetcode-cn.com/problems/minimum-moves-to-make-array-complementary) | 使数组互补的最少操作次数 |  | `数组`,`哈希表`,`前缀和` | 中等 |  |  |
| [1675](https://leetcode-cn.com/problems/minimize-deviation-in-array) | 数组的最小偏移量 |  | `贪心`,`数组`,`有序集合`,`堆（优先队列）` | 困难 |  |  |
| [1676](https://leetcode-cn.com/problems/lowest-common-ancestor-of-a-binary-tree-iv) | 二叉树的最近公共祖先 IV |  | `树`,`深度优先搜索`,`二叉树` | 中等 | 🔒 |  |
| [1677](https://leetcode-cn.com/problems/products-worth-over-invoices) | 发票中的产品金额 |  | `数据库` | 简单 | 🔒 |  |
| [1678](https://leetcode-cn.com/problems/goal-parser-interpretation) | 设计 Goal 解析器 |  | `字符串` | 简单 |  |  |
| [1679](https://leetcode-cn.com/problems/max-number-of-k-sum-pairs) | K 和数对的最大数目 |  | `数组`,`哈希表`,`双指针`,`排序` | 中等 |  |  |
| [1680](https://leetcode-cn.com/problems/concatenation-of-consecutive-binary-numbers) | 连接连续二进制数字 |  | `位运算`,`数学`,`模拟` | 中等 |  |  |
| [1681](https://leetcode-cn.com/problems/minimum-incompatibility) | 最小不兼容性 |  | `位运算`,`数组`,`动态规划`,`状态压缩` | 困难 |  |  |
| [1682](https://leetcode-cn.com/problems/longest-palindromic-subsequence-ii) | 最长回文子序列 II |  | `字符串`,`动态规划` | 中等 | 🔒 |  |
| [1683](https://leetcode-cn.com/problems/invalid-tweets) | 无效的推文 |  | `数据库` | 简单 | 🔒 |  |
| [1684](https://leetcode-cn.com/problems/count-the-number-of-consistent-strings) | 统计一致字符串的数目 |  | `位运算`,`数组`,`哈希表`,`字符串` | 简单 |  |  |
| [1685](https://leetcode-cn.com/problems/sum-of-absolute-differences-in-a-sorted-array) | 有序数组中差绝对值之和 |  | `数组`,`数学`,`前缀和` | 中等 |  |  |
| [1686](https://leetcode-cn.com/problems/stone-game-vi) | 石子游戏 VI |  | `贪心`,`数组`,`数学`,`博弈`,`排序`,`堆（优先队列）` | 中等 |  |  |
| [1687](https://leetcode-cn.com/problems/delivering-boxes-from-storage-to-ports) | 从仓库到码头运输箱子 |  | `线段树`,`队列`,`数组`,`动态规划`,`单调队列`,`堆（优先队列）` | 困难 |  |  |
| [1688](https://leetcode-cn.com/problems/count-of-matches-in-tournament) | 比赛中的配对次数 |  | `数学`,`模拟` | 简单 |  |  |
| [1689](https://leetcode-cn.com/problems/partitioning-into-minimum-number-of-deci-binary-numbers) | 十-二进制数的最少数目 |  | `贪心`,`字符串` | 中等 |  |  |
| [1690](https://leetcode-cn.com/problems/stone-game-vii) | 石子游戏 VII |  | `数组`,`数学`,`动态规划`,`博弈` | 中等 |  |  |
| [1691](https://leetcode-cn.com/problems/maximum-height-by-stacking-cuboids) | 堆叠长方体的最大高度 |  | `数组`,`动态规划`,`排序` | 困难 |  |  |
| [1692](https://leetcode-cn.com/problems/count-ways-to-distribute-candies) | 计算分配糖果的不同方式 |  | `动态规划` | 困难 | 🔒 |  |
| [1693](https://leetcode-cn.com/problems/daily-leads-and-partners) | 每天的领导和合伙人 |  | `数据库` | 简单 | 🔒 |  |
| [1694](https://leetcode-cn.com/problems/reformat-phone-number) | 重新格式化电话号码 |  | `字符串` | 简单 |  |  |
| [1695](https://leetcode-cn.com/problems/maximum-erasure-value) | 删除子数组的最大得分 |  | `数组`,`哈希表`,`滑动窗口` | 中等 |  |  |
| [1696](https://leetcode-cn.com/problems/jump-game-vi) | 跳跃游戏 VI |  | `队列`,`数组`,`动态规划`,`滑动窗口`,`单调队列`,`堆（优先队列）` | 中等 |  |  |
| [1697](https://leetcode-cn.com/problems/checking-existence-of-edge-length-limited-paths) | 检查边长度限制的路径是否存在 |  | `并查集`,`图`,`数组`,`排序` | 困难 |  |  |
| [1698](https://leetcode-cn.com/problems/number-of-distinct-substrings-in-a-string) | 字符串的不同子字符串个数 |  | `字典树`,`字符串`,`后缀数组`,`哈希函数`,`滚动哈希` | 中等 | 🔒 |  |
| [1699](https://leetcode-cn.com/problems/number-of-calls-between-two-persons) | 两人之间的通话次数 |  | `数据库` | 中等 | 🔒 |  |
| [1700](https://leetcode-cn.com/problems/number-of-students-unable-to-eat-lunch) | 无法吃午餐的学生数量 |  | `栈`,`队列`,`数组`,`模拟` | 简单 |  |  |
| [1701](https://leetcode-cn.com/problems/average-waiting-time) | 平均等待时间 |  | `数组`,`模拟` | 中等 |  |  |
| [1702](https://leetcode-cn.com/problems/maximum-binary-string-after-change) | 修改后的最大二进制字符串 |  | `贪心`,`字符串` | 中等 |  |  |
| [1703](https://leetcode-cn.com/problems/minimum-adjacent-swaps-for-k-consecutive-ones) | 得到连续 K 个 1 的最少相邻交换次数 |  | `贪心`,`数组`,`前缀和`,`滑动窗口` | 困难 |  |  |
| [1704](https://leetcode-cn.com/problems/determine-if-string-halves-are-alike) | 判断字符串的两半是否相似 |  | `字符串`,`计数` | 简单 |  |  |
| [1705](https://leetcode-cn.com/problems/maximum-number-of-eaten-apples) | 吃苹果的最大数目 |  | `贪心`,`数组`,`堆（优先队列）` | 中等 |  |  |
| [1706](https://leetcode-cn.com/problems/where-will-the-ball-fall) | 球会落何处 |  | `深度优先搜索`,`数组`,`动态规划`,`矩阵`,`模拟` | 中等 |  |  |
| [1707](https://leetcode-cn.com/problems/maximum-xor-with-an-element-from-array) | 与数组中元素的最大异或值 |  | `位运算`,`字典树`,`数组` | 困难 |  |  |
| [1708](https://leetcode-cn.com/problems/largest-subarray-length-k) | 长度为 K 的最大子数组 |  | `贪心`,`数组` | 简单 | 🔒 |  |
| [1709](https://leetcode-cn.com/problems/biggest-window-between-visits) | 访问日期之间最大的空档期 |  | `数据库` | 中等 | 🔒 |  |
| [1710](https://leetcode-cn.com/problems/maximum-units-on-a-truck) | 卡车上的最大单元数 |  | `贪心`,`数组`,`排序` | 简单 |  |  |
| [1711](https://leetcode-cn.com/problems/count-good-meals) | 大餐计数 |  | `数组`,`哈希表` | 中等 |  |  |
| [1712](https://leetcode-cn.com/problems/ways-to-split-array-into-three-subarrays) | 将数组分成三个子数组的方案数 |  | `数组`,`双指针`,`二分查找`,`前缀和` | 中等 |  |  |
| [1713](https://leetcode-cn.com/problems/minimum-operations-to-make-a-subsequence) | 得到子序列的最少操作次数 |  | `贪心`,`数组`,`哈希表`,`二分查找` | 困难 |  |  |
| [1714](https://leetcode-cn.com/problems/sum-of-special-evenly-spaced-elements-in-array) | 数组中特殊等间距元素的和 |  | `数组`,`动态规划` | 困难 | 🔒 |  |
| [1715](https://leetcode-cn.com/problems/count-apples-and-oranges) | 苹果和橘子的个数 |  | `数据库` | 中等 | 🔒 |  |
| [1716](https://leetcode-cn.com/problems/calculate-money-in-leetcode-bank) | 计算力扣银行的钱 |  | `数学` | 简单 |  |  |
| [1717](https://leetcode-cn.com/problems/maximum-score-from-removing-substrings) | 删除子字符串的最大得分 |  | `栈`,`贪心`,`字符串` | 中等 |  |  |
| [1718](https://leetcode-cn.com/problems/construct-the-lexicographically-largest-valid-sequence) | 构建字典序最大的可行序列 |  | `数组`,`回溯` | 中等 |  |  |
| [1719](https://leetcode-cn.com/problems/number-of-ways-to-reconstruct-a-tree) | 重构一棵树的方案数 |  | `树`,`图`,`拓扑排序` | 困难 |  |  |
| [1720](https://leetcode-cn.com/problems/decode-xored-array) | 解码异或后的数组 |  | `位运算`,`数组` | 简单 |  |  |
| [1721](https://leetcode-cn.com/problems/swapping-nodes-in-a-linked-list) | 交换链表中的节点 |  | `链表`,`双指针` | 中等 |  |  |
| [1722](https://leetcode-cn.com/problems/minimize-hamming-distance-after-swap-operations) | 执行交换操作后的最小汉明距离 |  | `深度优先搜索`,`并查集`,`数组` | 中等 |  |  |
| [1723](https://leetcode-cn.com/problems/find-minimum-time-to-finish-all-jobs) | 完成所有工作的最短时间 |  | `位运算`,`数组`,`动态规划`,`回溯`,`状态压缩` | 困难 |  |  |
| [1724](https://leetcode-cn.com/problems/checking-existence-of-edge-length-limited-paths-ii) | 检查边长度限制的路径是否存在 II |  | `并查集`,`图`,`最小生成树` | 困难 | 🔒 |  |
| [1725](https://leetcode-cn.com/problems/number-of-rectangles-that-can-form-the-largest-square) | 可以形成最大正方形的矩形数目 |  | `数组` | 简单 |  |  |
| [1726](https://leetcode-cn.com/problems/tuple-with-same-product) | 同积元组 |  | `数组`,`哈希表` | 中等 |  |  |
| [1727](https://leetcode-cn.com/problems/largest-submatrix-with-rearrangements) | 重新排列后的最大子矩阵 |  | `贪心`,`数组`,`矩阵`,`排序` | 中等 |  |  |
| [1728](https://leetcode-cn.com/problems/cat-and-mouse-ii) | 猫和老鼠 II |  | `广度优先搜索`,`图`,`记忆化搜索`,`数学`,`动态规划`,`博弈` | 困难 |  |  |
| [1729](https://leetcode-cn.com/problems/find-followers-count) | 求关注者的数量 |  | `数据库` | 简单 | 🔒 |  |
| [1730](https://leetcode-cn.com/problems/shortest-path-to-get-food) | 获取食物的最短路径 |  | `广度优先搜索`,`数组`,`矩阵` | 中等 | 🔒 |  |
| [1731](https://leetcode-cn.com/problems/the-number-of-employees-which-report-to-each-employee) | 每位经理的下属员工数量 |  | `数据库` | 简单 | 🔒 |  |
| [1732](https://leetcode-cn.com/problems/find-the-highest-altitude) | 找到最高海拔 |  | `数组`,`前缀和` | 简单 |  |  |
| [1733](https://leetcode-cn.com/problems/minimum-number-of-people-to-teach) | 需要教语言的最少人数 |  | `贪心`,`数组` | 中等 |  |  |
| [1734](https://leetcode-cn.com/problems/decode-xored-permutation) | 解码异或后的排列 |  | `位运算`,`数组` | 中等 |  |  |
| [1735](https://leetcode-cn.com/problems/count-ways-to-make-array-with-product) | 生成乘积数组的方案数 |  | `数组`,`数学`,`动态规划` | 困难 |  |  |
| [1736](https://leetcode-cn.com/problems/latest-time-by-replacing-hidden-digits) | 替换隐藏数字得到的最晚时间 |  | `字符串` | 简单 |  |  |
| [1737](https://leetcode-cn.com/problems/change-minimum-characters-to-satisfy-one-of-three-conditions) | 满足三条件之一需改变的最少字符数 |  | `哈希表`,`字符串`,`计数`,`前缀和` | 中等 |  |  |
| [1738](https://leetcode-cn.com/problems/find-kth-largest-xor-coordinate-value) | 找出第 K 大的异或坐标值 |  | `位运算`,`数组`,`分治`,`矩阵`,`前缀和`,`快速选择`,`堆（优先队列）` | 中等 |  |  |
| [1739](https://leetcode-cn.com/problems/building-boxes) | 放置盒子 |  | `贪心`,`数学`,`二分查找` | 困难 |  |  |
| [1740](https://leetcode-cn.com/problems/find-distance-in-a-binary-tree) | 找到二叉树中的距离 |  | `树`,`深度优先搜索`,`广度优先搜索`,`哈希表`,`二叉树` | 中等 | 🔒 |  |
| [1741](https://leetcode-cn.com/problems/find-total-time-spent-by-each-employee) | 查找每个员工花费的总时间 |  | `数据库` | 简单 | 🔒 |  |
| [1742](https://leetcode-cn.com/problems/maximum-number-of-balls-in-a-box) | 盒子中小球的最大数量 |  | `哈希表`,`数学`,`计数` | 简单 |  |  |
| [1743](https://leetcode-cn.com/problems/restore-the-array-from-adjacent-pairs) | 从相邻元素对还原数组 |  | `数组`,`哈希表` | 中等 |  |  |
| [1744](https://leetcode-cn.com/problems/can-you-eat-your-favorite-candy-on-your-favorite-day) | 你能在你最喜欢的那天吃到你最喜欢的糖果吗？ |  | `数组`,`前缀和` | 中等 |  |  |
| [1745](https://leetcode-cn.com/problems/palindrome-partitioning-iv) | 回文串分割 IV |  | `字符串`,`动态规划` | 困难 |  |  |
| [1746](https://leetcode-cn.com/problems/maximum-subarray-sum-after-one-operation) | 经过一次操作后的最大子数组和 |  | `数组`,`动态规划` | 中等 | 🔒 |  |
| [1747](https://leetcode-cn.com/problems/leetflex-banned-accounts) | 应该被禁止的Leetflex账户 |  | `数据库` | 中等 | 🔒 |  |
| [1748](https://leetcode-cn.com/problems/sum-of-unique-elements) | 唯一元素的和 |  | `数组`,`哈希表`,`计数` | 简单 |  |  |
| [1749](https://leetcode-cn.com/problems/maximum-absolute-sum-of-any-subarray) | 任意子数组和的绝对值的最大值 |  | `数组`,`动态规划` | 中等 |  |  |
| [1750](https://leetcode-cn.com/problems/minimum-length-of-string-after-deleting-similar-ends) | 删除字符串两端相同字符后的最短长度 |  | `双指针`,`字符串` | 中等 |  |  |
| [1751](https://leetcode-cn.com/problems/maximum-number-of-events-that-can-be-attended-ii) | 最多可以参加的会议数目 II |  | `数组`,`二分查找`,`动态规划` | 困难 |  |  |
| [1752](https://leetcode-cn.com/problems/check-if-array-is-sorted-and-rotated) | 检查数组是否经排序和轮转得到 |  | `数组` | 简单 |  |  |
| [1753](https://leetcode-cn.com/problems/maximum-score-from-removing-stones) | 移除石子的最大得分 |  | `贪心`,`数学`,`堆（优先队列）` | 中等 |  |  |
| [1754](https://leetcode-cn.com/problems/largest-merge-of-two-strings) | 构造字典序最大的合并字符串 |  | `贪心`,`双指针`,`字符串` | 中等 |  |  |
| [1755](https://leetcode-cn.com/problems/closest-subsequence-sum) | 最接近目标值的子序列和 |  | `位运算`,`数组`,`双指针`,`动态规划`,`状态压缩` | 困难 |  |  |
| [1756](https://leetcode-cn.com/problems/design-most-recently-used-queue) | 设计最近使用（MRU）队列 |  | `栈`,`设计`,`数组`,`哈希表`,`有序集合` | 中等 | 🔒 |  |
| [1757](https://leetcode-cn.com/problems/recyclable-and-low-fat-products) | 可回收且低脂的产品 |  | `数据库` | 简单 | 🔒 |  |
| [1758](https://leetcode-cn.com/problems/minimum-changes-to-make-alternating-binary-string) | 生成交替二进制字符串的最少操作数 |  | `字符串` | 简单 |  |  |
| [1759](https://leetcode-cn.com/problems/count-number-of-homogenous-substrings) | 统计同构子字符串的数目 |  | `数学`,`字符串` | 中等 |  |  |
| [1760](https://leetcode-cn.com/problems/minimum-limit-of-balls-in-a-bag) | 袋子里最少数目的球 |  | `数组`,`二分查找` | 中等 |  |  |
| [1761](https://leetcode-cn.com/problems/minimum-degree-of-a-connected-trio-in-a-graph) | 一个图中连通三元组的最小度数 |  | `图` | 困难 |  |  |
| [1762](https://leetcode-cn.com/problems/buildings-with-an-ocean-view) | 能看到海景的建筑物 |  | `栈`,`数组`,`单调栈` | 中等 | 🔒 |  |
| [1763](https://leetcode-cn.com/problems/longest-nice-substring) | 最长的美好子字符串 |  | `位运算`,`哈希表`,`字符串`,`滑动窗口` | 简单 |  |  |
| [1764](https://leetcode-cn.com/problems/form-array-by-concatenating-subarrays-of-another-array) | 通过连接另一个数组的子数组得到一个数组 |  | `贪心`,`数组`,`字符串匹配` | 中等 |  |  |
| [1765](https://leetcode-cn.com/problems/map-of-highest-peak) | 地图中的最高点 |  | `广度优先搜索`,`数组`,`矩阵` | 中等 |  |  |
| [1766](https://leetcode-cn.com/problems/tree-of-coprimes) | 互质树 |  | `树`,`深度优先搜索`,`广度优先搜索`,`数学` | 困难 |  |  |
| [1767](https://leetcode-cn.com/problems/find-the-subtasks-that-did-not-execute) | 寻找没有被执行的任务对 |  | `数据库` | 困难 | 🔒 |  |
| [1768](https://leetcode-cn.com/problems/merge-strings-alternately) | 交替合并字符串 |  | `双指针`,`字符串` | 简单 |  |  |
| [1769](https://leetcode-cn.com/problems/minimum-number-of-operations-to-move-all-balls-to-each-box) | 移动所有球到每个盒子所需的最小操作数 |  | `数组`,`字符串` | 中等 |  |  |
| [1770](https://leetcode-cn.com/problems/maximum-score-from-performing-multiplication-operations) | 执行乘法运算的最大分数 |  | `数组`,`动态规划` | 中等 |  |  |
| [1771](https://leetcode-cn.com/problems/maximize-palindrome-length-from-subsequences) | 由子序列构造的最长回文串的长度 |  | `字符串`,`动态规划` | 困难 |  |  |
| [1772](https://leetcode-cn.com/problems/sort-features-by-popularity) | 按受欢迎程度排列功能 |  | `数组`,`哈希表`,`字符串`,`排序` | 中等 | 🔒 |  |
| [1773](https://leetcode-cn.com/problems/count-items-matching-a-rule) | 统计匹配检索规则的物品数量 |  | `数组`,`字符串` | 简单 |  |  |
| [1774](https://leetcode-cn.com/problems/closest-dessert-cost) | 最接近目标价格的甜点成本 |  | `数组`,`动态规划`,`回溯` | 中等 |  |  |
| [1775](https://leetcode-cn.com/problems/equal-sum-arrays-with-minimum-number-of-operations) | 通过最少操作次数使数组的和相等 |  | `贪心`,`数组`,`哈希表`,`计数` | 中等 |  |  |
| [1776](https://leetcode-cn.com/problems/car-fleet-ii) | 车队 II |  | `栈`,`数组`,`数学`,`单调栈`,`堆（优先队列）` | 困难 |  |  |
| [1777](https://leetcode-cn.com/problems/products-price-for-each-store) | 每家商店的产品价格 |  | `数据库` | 简单 | 🔒 |  |
| [1778](https://leetcode-cn.com/problems/shortest-path-in-a-hidden-grid) | 未知网格中的最短路径 |  | `深度优先搜索`,`广度优先搜索`,`图`,`交互` | 中等 | 🔒 |  |
| [1779](https://leetcode-cn.com/problems/find-nearest-point-that-has-the-same-x-or-y-coordinate) | 找到最近的有相同 X 或 Y 坐标的点 |  | `数组` | 简单 |  |  |
| [1780](https://leetcode-cn.com/problems/check-if-number-is-a-sum-of-powers-of-three) | 判断一个数字是否可以表示成三的幂的和 |  | `数学` | 中等 |  |  |
| [1781](https://leetcode-cn.com/problems/sum-of-beauty-of-all-substrings) | 所有子字符串美丽值之和 |  | `哈希表`,`字符串`,`计数` | 中等 |  |  |
| [1782](https://leetcode-cn.com/problems/count-pairs-of-nodes) | 统计点对的数目 |  | `图`,`双指针`,`二分查找` | 困难 |  |  |
| [1783](https://leetcode-cn.com/problems/grand-slam-titles) | 大满贯数量 |  | `数据库` | 中等 | 🔒 |  |
| [1784](https://leetcode-cn.com/problems/check-if-binary-string-has-at-most-one-segment-of-ones) | 检查二进制字符串字段 |  | `字符串` | 简单 |  |  |
| [1785](https://leetcode-cn.com/problems/minimum-elements-to-add-to-form-a-given-sum) | 构成特定和需要添加的最少元素 |  | `贪心`,`数组` | 中等 |  |  |
| [1786](https://leetcode-cn.com/problems/number-of-restricted-paths-from-first-to-last-node) | 从第一个节点出发到最后一个节点的受限路径数 |  | `图`,`拓扑排序`,`动态规划`,`最短路`,`堆（优先队列）` | 中等 |  |  |
| [1787](https://leetcode-cn.com/problems/make-the-xor-of-all-segments-equal-to-zero) | 使所有区间的异或结果为零 |  | `位运算`,`数组`,`动态规划` | 困难 |  |  |
| [1788](https://leetcode-cn.com/problems/maximize-the-beauty-of-the-garden) | 最大化花园的美观度 |  | `贪心`,`数组`,`前缀和` | 困难 | 🔒 |  |
| [1789](https://leetcode-cn.com/problems/primary-department-for-each-employee) | 员工的直属部门 |  | `数据库` | 简单 | 🔒 |  |
| [1790](https://leetcode-cn.com/problems/check-if-one-string-swap-can-make-strings-equal) | 仅执行一次字符串交换能否使两个字符串相等 |  | `哈希表`,`字符串`,`计数` | 简单 |  |  |
| [1791](https://leetcode-cn.com/problems/find-center-of-star-graph) | 找出星型图的中心节点 |  | `图` | 简单 |  |  |
| [1792](https://leetcode-cn.com/problems/maximum-average-pass-ratio) | 最大平均通过率 |  | `贪心`,`数组`,`堆（优先队列）` | 中等 |  |  |
| [1793](https://leetcode-cn.com/problems/maximum-score-of-a-good-subarray) | 好子数组的最大分数 |  | `栈`,`数组`,`双指针`,`单调栈` | 困难 |  |  |
| [1794](https://leetcode-cn.com/problems/count-pairs-of-equal-substrings-with-minimum-difference) | 统计距离最小的子串对个数 |  | `贪心`,`哈希表`,`字符串` | 中等 | 🔒 |  |
| [1795](https://leetcode-cn.com/problems/rearrange-products-table) | 每个产品在不同商店的价格 |  | `数据库` | 简单 | 🔒 |  |
| [1796](https://leetcode-cn.com/problems/second-largest-digit-in-a-string) | 字符串中第二大的数字 |  | `哈希表`,`字符串` | 简单 |  |  |
| [1797](https://leetcode-cn.com/problems/design-authentication-manager) | 设计一个验证系统 |  | `设计`,`哈希表` | 中等 |  |  |
| [1798](https://leetcode-cn.com/problems/maximum-number-of-consecutive-values-you-can-make) | 你能构造出连续值的最大数目 |  | `贪心`,`数组` | 中等 |  |  |
| [1799](https://leetcode-cn.com/problems/maximize-score-after-n-operations) | N 次操作后的最大分数和 |  | `位运算`,`数组`,`数学`,`动态规划`,`回溯`,`状态压缩`,`数论` | 困难 |  |  |
| [1800](https://leetcode-cn.com/problems/maximum-ascending-subarray-sum) | 最大升序子数组和 |  | `数组` | 简单 |  |  |
| [1801](https://leetcode-cn.com/problems/number-of-orders-in-the-backlog) | 积压订单中的订单总数 |  | `数组`,`模拟`,`堆（优先队列）` | 中等 |  |  |
| [1802](https://leetcode-cn.com/problems/maximum-value-at-a-given-index-in-a-bounded-array) | 有界数组中指定下标处的最大值 |  | `贪心`,`二分查找` | 中等 |  |  |
| [1803](https://leetcode-cn.com/problems/count-pairs-with-xor-in-a-range) | 统计异或值在范围内的数对有多少 |  | `位运算`,`字典树`,`数组` | 困难 |  |  |
| [1804](https://leetcode-cn.com/problems/implement-trie-ii-prefix-tree) | 实现 Trie （前缀树） II |  | `设计`,`字典树`,`哈希表`,`字符串` | 中等 | 🔒 |  |
| [1805](https://leetcode-cn.com/problems/number-of-different-integers-in-a-string) | 字符串中不同整数的数目 |  | `哈希表`,`字符串` | 简单 |  |  |
| [1806](https://leetcode-cn.com/problems/minimum-number-of-operations-to-reinitialize-a-permutation) | 还原排列的最少操作步数 |  | `数组`,`数学`,`模拟` | 中等 |  |  |
| [1807](https://leetcode-cn.com/problems/evaluate-the-bracket-pairs-of-a-string) | 替换字符串中的括号内容 |  | `数组`,`哈希表`,`字符串` | 中等 |  |  |
| [1808](https://leetcode-cn.com/problems/maximize-number-of-nice-divisors) | 好因子的最大数目 |  | `递归`,`数学` | 困难 |  |  |
| [1809](https://leetcode-cn.com/problems/ad-free-sessions) | 没有广告的剧集 |  | `数据库` | 简单 | 🔒 |  |
| [1810](https://leetcode-cn.com/problems/minimum-path-cost-in-a-hidden-grid) | 隐藏网格下的最小消耗路径 |  | `深度优先搜索`,`广度优先搜索`,`图`,`交互`,`堆（优先队列）` | 中等 | 🔒 |  |
| [1811](https://leetcode-cn.com/problems/find-interview-candidates) | 寻找面试候选人 |  | `数据库` | 中等 | 🔒 |  |
| [1812](https://leetcode-cn.com/problems/determine-color-of-a-chessboard-square) | 判断国际象棋棋盘中一个格子的颜色 |  | `数学`,`字符串` | 简单 |  |  |
| [1813](https://leetcode-cn.com/problems/sentence-similarity-iii) | 句子相似性 III |  | `数组`,`双指针`,`字符串` | 中等 |  |  |
| [1814](https://leetcode-cn.com/problems/count-nice-pairs-in-an-array) | 统计一个数组中好对子的数目 |  | `数组`,`哈希表`,`数学`,`计数` | 中等 |  |  |
| [1815](https://leetcode-cn.com/problems/maximum-number-of-groups-getting-fresh-donuts) | 得到新鲜甜甜圈的最多组数 |  | `位运算`,`记忆化搜索`,`数组`,`动态规划`,`状态压缩` | 困难 |  |  |
| [1816](https://leetcode-cn.com/problems/truncate-sentence) | 截断句子 |  | `数组`,`字符串` | 简单 |  |  |
| [1817](https://leetcode-cn.com/problems/finding-the-users-active-minutes) | 查找用户活跃分钟数 |  | `数组`,`哈希表` | 中等 |  |  |
| [1818](https://leetcode-cn.com/problems/minimum-absolute-sum-difference) | 绝对差值和 |  | `贪心`,`数组`,`二分查找`,`有序集合` | 中等 |  |  |
| [1819](https://leetcode-cn.com/problems/number-of-different-subsequences-gcds) | 序列中不同最大公约数的数目 |  | `数组`,`数学`,`计数`,`数论` | 困难 |  |  |
| [1820](https://leetcode-cn.com/problems/maximum-number-of-accepted-invitations) | 最多邀请的个数 |  | `数组`,`回溯`,`矩阵` | 中等 | 🔒 |  |
| [1821](https://leetcode-cn.com/problems/find-customers-with-positive-revenue-this-year) | 寻找今年具有正收入的客户 |  | `数据库` | 简单 | 🔒 |  |
| [1822](https://leetcode-cn.com/problems/sign-of-the-product-of-an-array) | 数组元素积的符号 |  | `数组`,`数学` | 简单 |  |  |
| [1823](https://leetcode-cn.com/problems/find-the-winner-of-the-circular-game) | 找出游戏的获胜者 |  | `递归`,`数组`,`数学`,`模拟` | 中等 |  |  |
| [1824](https://leetcode-cn.com/problems/minimum-sideway-jumps) | 最少侧跳次数 |  | `贪心`,`数组`,`动态规划` | 中等 |  |  |
| [1825](https://leetcode-cn.com/problems/finding-mk-average) | 求出 MK 平均值 |  | `设计`,`队列`,`有序集合`,`堆（优先队列）` | 困难 |  |  |
| [1826](https://leetcode-cn.com/problems/faulty-sensor) | 有缺陷的传感器 |  | `数组`,`双指针` | 简单 | 🔒 |  |
| [1827](https://leetcode-cn.com/problems/minimum-operations-to-make-the-array-increasing) | 最少操作使数组递增 |  | `贪心`,`数组` | 简单 |  |  |
| [1828](https://leetcode-cn.com/problems/queries-on-number-of-points-inside-a-circle) | 统计一个圆中点的数目 |  | `几何`,`数组`,`数学` | 中等 |  |  |
| [1829](https://leetcode-cn.com/problems/maximum-xor-for-each-query) | 每个查询的最大异或值 |  | `位运算`,`数组`,`前缀和` | 中等 |  |  |
| [1830](https://leetcode-cn.com/problems/minimum-number-of-operations-to-make-string-sorted) | 使字符串有序的最少操作次数 |  | `数学`,`字符串`,`组合数学` | 困难 |  |  |
| [1831](https://leetcode-cn.com/problems/maximum-transaction-each-day) | 每天的最大交易 |  | `数据库` | 中等 | 🔒 |  |
| [1832](https://leetcode-cn.com/problems/check-if-the-sentence-is-pangram) | 判断句子是否为全字母句 |  | `哈希表`,`字符串` | 简单 |  |  |
| [1833](https://leetcode-cn.com/problems/maximum-ice-cream-bars) | 雪糕的最大数量 |  | `贪心`,`数组`,`排序` | 中等 |  |  |
| [1834](https://leetcode-cn.com/problems/single-threaded-cpu) | 单线程 CPU |  | `数组`,`排序`,`堆（优先队列）` | 中等 |  |  |
| [1835](https://leetcode-cn.com/problems/find-xor-sum-of-all-pairs-bitwise-and) | 所有数对按位与结果的异或和 |  | `位运算`,`数组`,`数学` | 困难 |  |  |
| [1836](https://leetcode-cn.com/problems/remove-duplicates-from-an-unsorted-linked-list) | 从未排序的链表中移除重复元素 |  | `哈希表`,`链表` | 中等 | 🔒 |  |
| [1837](https://leetcode-cn.com/problems/sum-of-digits-in-base-k) | K 进制表示下的各位数字总和 |  | `数学` | 简单 |  |  |
| [1838](https://leetcode-cn.com/problems/frequency-of-the-most-frequent-element) | 最高频元素的频数 |  | `数组`,`二分查找`,`前缀和`,`滑动窗口` | 中等 |  |  |
| [1839](https://leetcode-cn.com/problems/longest-substring-of-all-vowels-in-order) | 所有元音按顺序排布的最长子字符串 |  | `字符串`,`滑动窗口` | 中等 |  |  |
| [1840](https://leetcode-cn.com/problems/maximum-building-height) | 最高建筑高度 |  | `数组`,`数学` | 困难 |  |  |
| [1841](https://leetcode-cn.com/problems/league-statistics) | 联赛信息统计 |  | `数据库` | 中等 | 🔒 |  |
| [1842](https://leetcode-cn.com/problems/next-palindrome-using-same-digits) | 下个由相同数字构成的回文串 |  | `双指针`,`字符串` | 困难 | 🔒 |  |
| [1843](https://leetcode-cn.com/problems/suspicious-bank-accounts) | Suspicious Bank Accounts |  | `数据库` | 中等 | 🔒 |  |
| [1844](https://leetcode-cn.com/problems/replace-all-digits-with-characters) | 将所有数字用字符替换 |  | `字符串` | 简单 |  |  |
| [1845](https://leetcode-cn.com/problems/seat-reservation-manager) | 座位预约管理系统 |  | `设计`,`堆（优先队列）` | 中等 |  |  |
| [1846](https://leetcode-cn.com/problems/maximum-element-after-decreasing-and-rearranging) | 减小和重新排列数组后的最大元素 |  | `贪心`,`数组`,`排序` | 中等 |  |  |
| [1847](https://leetcode-cn.com/problems/closest-room) | 最近的房间 |  | `数组`,`二分查找`,`排序` | 困难 |  |  |
| [1848](https://leetcode-cn.com/problems/minimum-distance-to-the-target-element) | 到目标元素的最小距离 |  | `数组` | 简单 |  |  |
| [1849](https://leetcode-cn.com/problems/splitting-a-string-into-descending-consecutive-values) | 将字符串拆分为递减的连续值 |  | `字符串`,`回溯` | 中等 |  |  |
| [1850](https://leetcode-cn.com/problems/minimum-adjacent-swaps-to-reach-the-kth-smallest-number) | 邻位交换的最小次数 |  | `贪心`,`双指针`,`字符串` | 中等 |  |  |
| [1851](https://leetcode-cn.com/problems/minimum-interval-to-include-each-query) | 包含每个查询的最小区间 |  | `数组`,`二分查找`,`排序`,`扫描线`,`堆（优先队列）` | 困难 |  |  |
| [1852](https://leetcode-cn.com/problems/distinct-numbers-in-each-subarray) | 每个子数组的数字种类数 |  | `数组`,`哈希表`,`滑动窗口` | 中等 | 🔒 |  |
| [1853](https://leetcode-cn.com/problems/convert-date-format) | 转换日期格式 |  | `数据库` | 简单 | 🔒 |  |
| [1854](https://leetcode-cn.com/problems/maximum-population-year) | 人口最多的年份 |  | `数组`,`计数` | 简单 |  |  |
| [1855](https://leetcode-cn.com/problems/maximum-distance-between-a-pair-of-values) | 下标对中的最大距离 |  | `贪心`,`数组`,`双指针`,`二分查找` | 中等 |  |  |
| [1856](https://leetcode-cn.com/problems/maximum-subarray-min-product) | 子数组最小乘积的最大值 |  | `栈`,`数组`,`前缀和`,`单调栈` | 中等 |  |  |
| [1857](https://leetcode-cn.com/problems/largest-color-value-in-a-directed-graph) | 有向图中最大颜色值 |  | `图`,`拓扑排序`,`记忆化搜索`,`哈希表`,`动态规划`,`计数` | 困难 |  |  |
| [1858](https://leetcode-cn.com/problems/longest-word-with-all-prefixes) | 包含所有前缀的最长单词 |  | `深度优先搜索`,`字典树` | 中等 | 🔒 |  |
| [1859](https://leetcode-cn.com/problems/sorting-the-sentence) | 将句子排序 |  | `字符串`,`排序` | 简单 |  |  |
| [1860](https://leetcode-cn.com/problems/incremental-memory-leak) | 增长的内存泄露 |  | `模拟` | 中等 |  |  |
| [1861](https://leetcode-cn.com/problems/rotating-the-box) | 旋转盒子 |  | `数组`,`双指针`,`矩阵` | 中等 |  |  |
| [1862](https://leetcode-cn.com/problems/sum-of-floored-pairs) | 向下取整数对和 |  | `数组`,`数学`,`二分查找`,`前缀和` | 困难 |  |  |
| [1863](https://leetcode-cn.com/problems/sum-of-all-subset-xor-totals) | 找出所有子集的异或总和再求和 |  | `位运算`,`数组`,`回溯` | 简单 |  |  |
| [1864](https://leetcode-cn.com/problems/minimum-number-of-swaps-to-make-the-binary-string-alternating) | 构成交替字符串需要的最小交换次数 |  | `贪心`,`字符串` | 中等 |  |  |
| [1865](https://leetcode-cn.com/problems/finding-pairs-with-a-certain-sum) | 找出和为指定值的下标对 |  | `设计`,`数组`,`哈希表` | 中等 |  |  |
| [1866](https://leetcode-cn.com/problems/number-of-ways-to-rearrange-sticks-with-k-sticks-visible) | 恰有 K 根木棍可以看到的排列数目 |  | `数学`,`动态规划`,`组合数学` | 困难 |  |  |
| [1867](https://leetcode-cn.com/problems/orders-with-maximum-quantity-above-average) | Orders With Maximum Quantity Above Average |  | `数据库` | 中等 | 🔒 |  |
| [1868](https://leetcode-cn.com/problems/product-of-two-run-length-encoded-arrays) | 两个行程编码数组的积 |  | `数组`,`双指针` | 中等 | 🔒 |  |
| [1869](https://leetcode-cn.com/problems/longer-contiguous-segments-of-ones-than-zeros) | 哪种连续子字符串更长 |  | `字符串` | 简单 |  |  |
| [1870](https://leetcode-cn.com/problems/minimum-speed-to-arrive-on-time) | 准时到达的列车最小时速 |  | `数组`,`二分查找` | 中等 |  |  |
| [1871](https://leetcode-cn.com/problems/jump-game-vii) | 跳跃游戏 VII |  | `双指针`,`字符串`,`前缀和` | 中等 |  |  |
| [1872](https://leetcode-cn.com/problems/stone-game-viii) | 石子游戏 VIII |  | `数组`,`数学`,`动态规划`,`博弈`,`前缀和` | 困难 |  |  |
| [1873](https://leetcode-cn.com/problems/calculate-special-bonus) | 计算特殊奖金 |  | `数据库` | 简单 | 🔒 |  |
| [1874](https://leetcode-cn.com/problems/minimize-product-sum-of-two-arrays) | 两个数组的最小乘积和 |  | `贪心`,`数组`,`排序` | 中等 | 🔒 |  |
| [1875](https://leetcode-cn.com/problems/group-employees-of-the-same-salary) | Group Employees of the Same Salary |  | `数据库` | 中等 | 🔒 |  |
| [1876](https://leetcode-cn.com/problems/substrings-of-size-three-with-distinct-characters) | 长度为三且各字符不同的子字符串 |  | `哈希表`,`字符串`,`计数`,`滑动窗口` | 简单 |  |  |
| [1877](https://leetcode-cn.com/problems/minimize-maximum-pair-sum-in-array) | 数组中最大数对和的最小值 |  | `贪心`,`数组`,`双指针`,`排序` | 中等 |  |  |
| [1878](https://leetcode-cn.com/problems/get-biggest-three-rhombus-sums-in-a-grid) | 矩阵中最大的三个菱形和 |  | `数组`,`数学`,`矩阵`,`前缀和`,`排序`,`堆（优先队列）` | 中等 |  |  |
| [1879](https://leetcode-cn.com/problems/minimum-xor-sum-of-two-arrays) | 两个数组最小的异或值之和 |  | `位运算`,`数组`,`动态规划`,`状态压缩` | 困难 |  |  |
| [1880](https://leetcode-cn.com/problems/check-if-word-equals-summation-of-two-words) | 检查某单词是否等于两单词之和 |  | `字符串` | 简单 |  |  |
| [1881](https://leetcode-cn.com/problems/maximum-value-after-insertion) | 插入后的最大值 |  | `贪心`,`字符串` | 中等 |  |  |
| [1882](https://leetcode-cn.com/problems/process-tasks-using-servers) | 使用服务器处理任务 |  | `数组`,`堆（优先队列）` | 中等 |  |  |
| [1883](https://leetcode-cn.com/problems/minimum-skips-to-arrive-at-meeting-on-time) | 准时抵达会议现场的最小跳过休息次数 |  | `数组`,`动态规划` | 困难 |  |  |
| [1884](https://leetcode-cn.com/problems/egg-drop-with-2-eggs-and-n-floors) | 鸡蛋掉落-两枚鸡蛋 |  | `数学`,`动态规划` | 中等 |  |  |
| [1885](https://leetcode-cn.com/problems/count-pairs-in-two-arrays) | Count Pairs in Two Arrays |  | `数组`,`二分查找`,`排序` | 中等 | 🔒 |  |
| [1886](https://leetcode-cn.com/problems/determine-whether-matrix-can-be-obtained-by-rotation) | 判断矩阵经轮转后是否一致 |  | `数组`,`矩阵` | 简单 |  |  |
| [1887](https://leetcode-cn.com/problems/reduction-operations-to-make-the-array-elements-equal) | 使数组元素相等的减少操作次数 |  | `数组`,`排序` | 中等 |  |  |
| [1888](https://leetcode-cn.com/problems/minimum-number-of-flips-to-make-the-binary-string-alternating) | 使二进制字符串字符交替的最少反转次数 |  | `贪心`,`字符串` | 中等 |  |  |
| [1889](https://leetcode-cn.com/problems/minimum-space-wasted-from-packaging) | 装包裹的最小浪费空间 |  | `数组`,`二分查找`,`前缀和`,`排序` | 困难 |  |  |
| [1890](https://leetcode-cn.com/problems/the-latest-login-in-2020) | 2020年最后一次登录 |  | `数据库` | 简单 | 🔒 |  |
| [1891](https://leetcode-cn.com/problems/cutting-ribbons) | 割绳子 |  | `数组`,`二分查找` | 中等 | 🔒 |  |
| [1892](https://leetcode-cn.com/problems/page-recommendations-ii) | 页面推荐Ⅱ |  | `数据库` | 困难 | 🔒 |  |
| [1893](https://leetcode-cn.com/problems/check-if-all-the-integers-in-a-range-are-covered) | 检查是否区域内所有整数都被覆盖 |  | `数组`,`哈希表`,`前缀和` | 简单 |  |  |
| [1894](https://leetcode-cn.com/problems/find-the-student-that-will-replace-the-chalk) | 找到需要补充粉笔的学生编号 |  | `数组`,`二分查找`,`前缀和`,`模拟` | 中等 |  |  |
| [1895](https://leetcode-cn.com/problems/largest-magic-square) | 最大的幻方 |  | `数组`,`矩阵`,`前缀和` | 中等 |  |  |
| [1896](https://leetcode-cn.com/problems/minimum-cost-to-change-the-final-value-of-expression) | 反转表达式值的最少操作次数 |  | `栈`,`数学`,`字符串`,`动态规划` | 困难 |  |  |
| [1897](https://leetcode-cn.com/problems/redistribute-characters-to-make-all-strings-equal) | 重新分配字符使所有字符串都相等 |  | `哈希表`,`字符串`,`计数` | 简单 |  |  |
| [1898](https://leetcode-cn.com/problems/maximum-number-of-removable-characters) | 可移除字符的最大数目 |  | `数组`,`字符串`,`二分查找` | 中等 |  |  |
| [1899](https://leetcode-cn.com/problems/merge-triplets-to-form-target-triplet) | 合并若干三元组以形成目标三元组 |  | `贪心`,`数组` | 中等 |  |  |
| [1900](https://leetcode-cn.com/problems/the-earliest-and-latest-rounds-where-players-compete) | 最佳运动员的比拼回合 |  | `记忆化搜索`,`动态规划` | 困难 |  |  |
| [1901](https://leetcode-cn.com/problems/find-a-peak-element-ii) | 找出顶峰元素 II |  | `数组`,`二分查找`,`分治`,`矩阵` | 中等 |  |  |
| [1902](https://leetcode-cn.com/problems/depth-of-bst-given-insertion-order) | Depth of BST Given Insertion Order |  | `树`,`二叉搜索树`,`二叉树`,`有序集合` | 中等 | 🔒 |  |
| [1903](https://leetcode-cn.com/problems/largest-odd-number-in-string) | 字符串中的最大奇数 |  | `贪心`,`数学`,`字符串` | 简单 |  |  |
| [1904](https://leetcode-cn.com/problems/the-number-of-full-rounds-you-have-played) | 你完成的完整对局数 |  | `数学`,`字符串` | 中等 |  |  |
| [1905](https://leetcode-cn.com/problems/count-sub-islands) | 统计子岛屿 |  | `深度优先搜索`,`广度优先搜索`,`并查集`,`数组`,`矩阵` | 中等 |  |  |
| [1906](https://leetcode-cn.com/problems/minimum-absolute-difference-queries) | 查询差绝对值的最小值 |  | `数组`,`哈希表` | 中等 |  |  |
| [1907](https://leetcode-cn.com/problems/count-salary-categories) | 按分类统计薪水 |  | `数据库` | 中等 | 🔒 |  |
| [1908](https://leetcode-cn.com/problems/game-of-nim) | Game of Nim |  | `位运算`,`脑筋急转弯`,`数组`,`数学`,`动态规划`,`博弈` | 中等 | 🔒 |  |
| [1909](https://leetcode-cn.com/problems/remove-one-element-to-make-the-array-strictly-increasing) | 删除一个元素使数组严格递增 |  | `数组` | 简单 |  |  |
| [1910](https://leetcode-cn.com/problems/remove-all-occurrences-of-a-substring) | 删除一个字符串中所有出现的给定子字符串 |  | `字符串` | 中等 |  |  |
| [1911](https://leetcode-cn.com/problems/maximum-alternating-subsequence-sum) | 最大子序列交替和 |  | `数组`,`动态规划` | 中等 |  |  |
| [1912](https://leetcode-cn.com/problems/design-movie-rental-system) | 设计电影租借系统 |  | `设计`,`数组`,`哈希表`,`有序集合`,`堆（优先队列）` | 困难 |  |  |
| [1913](https://leetcode-cn.com/problems/maximum-product-difference-between-two-pairs) | 两个数对之间的最大乘积差 |  | `数组`,`排序` | 简单 |  |  |
| [1914](https://leetcode-cn.com/problems/cyclically-rotating-a-grid) | 循环轮转矩阵 |  | `数组`,`矩阵`,`模拟` | 中等 |  |  |
| [1915](https://leetcode-cn.com/problems/number-of-wonderful-substrings) | 最美子字符串的数目 |  | `位运算`,`哈希表`,`字符串`,`前缀和` | 中等 |  |  |
| [1916](https://leetcode-cn.com/problems/count-ways-to-build-rooms-in-an-ant-colony) | 统计为蚁群构筑房间的不同顺序 |  | `树`,`图`,`拓扑排序`,`数学`,`动态规划`,`组合数学` | 困难 |  |  |
| [1917](https://leetcode-cn.com/problems/leetcodify-friends-recommendations) | Leetcodify Friends Recommendations |  | `数据库` | 困难 | 🔒 |  |
| [1918](https://leetcode-cn.com/problems/kth-smallest-subarray-sum) | Kth Smallest Subarray Sum |  | `数组`,`二分查找`,`滑动窗口` | 中等 | 🔒 |  |
| [1919](https://leetcode-cn.com/problems/leetcodify-similar-friends) | 兴趣相同的朋友 |  |  | 困难 | 🔒 |  |
| [1920](https://leetcode-cn.com/problems/build-array-from-permutation) | 基于排列构建数组 |  | `数组`,`模拟` | 简单 |  |  |
| [1921](https://leetcode-cn.com/problems/eliminate-maximum-number-of-monsters) | 消灭怪物的最大数量 |  | `贪心`,`数组`,`排序` | 中等 |  |  |
| [1922](https://leetcode-cn.com/problems/count-good-numbers) | 统计好数字的数目 |  | `递归`,`数学` | 中等 |  |  |
| [1923](https://leetcode-cn.com/problems/longest-common-subpath) | 最长公共子路径 |  | `数组`,`二分查找`,`后缀数组`,`哈希函数`,`滚动哈希` | 困难 |  |  |
| [1924](https://leetcode-cn.com/problems/erect-the-fence-ii) | Erect the Fence II |  |  | 困难 | 🔒 |  |
| [1925](https://leetcode-cn.com/problems/count-square-sum-triples) | 统计平方和三元组的数目 |  | `数学`,`枚举` | 简单 |  |  |
| [1926](https://leetcode-cn.com/problems/nearest-exit-from-entrance-in-maze) | 迷宫中离入口最近的出口 |  | `广度优先搜索`,`数组`,`矩阵` | 中等 |  |  |
| [1927](https://leetcode-cn.com/problems/sum-game) | 求和游戏 |  | `贪心`,`数学`,`博弈` | 中等 |  |  |
| [1928](https://leetcode-cn.com/problems/minimum-cost-to-reach-destination-in-time) | 规定时间内到达终点的最小花费 |  | `图`,`动态规划` | 困难 |  |  |
| [1929](https://leetcode-cn.com/problems/concatenation-of-array) | 数组串联 |  | `数组` | 简单 |  |  |
| [1930](https://leetcode-cn.com/problems/unique-length-3-palindromic-subsequences) | 长度为 3 的不同回文子序列 |  | `哈希表`,`字符串`,`前缀和` | 中等 |  |  |
| [1931](https://leetcode-cn.com/problems/painting-a-grid-with-three-different-colors) | 用三种不同颜色为网格涂色 |  | `动态规划` | 困难 |  |  |
| [1932](https://leetcode-cn.com/problems/merge-bsts-to-create-single-bst) | 合并多棵二叉搜索树 |  | `树`,`深度优先搜索`,`哈希表`,`二分查找`,`二叉树` | 困难 |  |  |
| [1933](https://leetcode-cn.com/problems/check-if-string-is-decomposable-into-value-equal-substrings) | 判断字符串是否可分解为值均等的子串 |  |  | 简单 | 🔒 |  |
| [1934](https://leetcode-cn.com/problems/confirmation-rate) | Confirmation Rate |  |  | 中等 | 🔒 |  |
| [1935](https://leetcode-cn.com/problems/maximum-number-of-words-you-can-type) | 可以输入的最大单词数 |  | `字符串` | 简单 |  |  |
| [1936](https://leetcode-cn.com/problems/add-minimum-number-of-rungs) | 新增的最少台阶数 |  |  | 中等 |  |  |
| [1937](https://leetcode-cn.com/problems/maximum-number-of-points-with-cost) | 扣分后的最大得分 |  |  | 中等 |  |  |
| [1938](https://leetcode-cn.com/problems/maximum-genetic-difference-query) | 查询最大基因差 |  |  | 困难 |  |  |
| [1939](https://leetcode-cn.com/problems/users-that-actively-request-confirmation-messages) | Users That Actively Request Confirmation Messages |  |  | 简单 |  |  |