0100._same_tree.md

100. Same Tree

难度: Easy

刷题内容

原题连接

• https://leetcode.com/problems/same-tree/description/

内容描述

Given two binary trees, write a function to check if they are the same or not.

Two binary trees are considered the same if they are structurally identical and the nodes have the same value.

Example 1:

Input:     1         1
          / \       / \
         2   3     2   3

        [1,2,3],   [1,2,3]

Output: true
Example 2:

Input:     1         1
          /           \
         2             2

        [1,2],     [1,null,2]

Output: false
Example 3:

Input:     1         1
          / \       / \
         2   1     1   2

        [1,2,1],   [1,1,2]

Output: false

解题方案

思路 1 - 时间复杂度: O(N)- 空间复杂度: O(1)******

递归

class Solution(object):
    def isSameTree(self, p, q):
        """
        :type p: TreeNode
        :type q: TreeNode
        :rtype: bool
        """
        if not p and not q:
            return True
        if (p and not q) or (not p and q):
            return False
        return p.val == q.val and self.isSameTree(p.left, q.left) and self.isSameTree(p.right, q.right)

一行版本

class Solution(object):
    def isSameTree(self, p, q):
        """
        :type p: TreeNode
        :type q: TreeNode
        :rtype: bool
        """
        return p.val == q.val and all(map(self.isSameTree, (p.left, p.right), (q.left, q.right))) if p and q else p is q