0104._maximum_depth_of_binary_tree.md

104. Maximum Depth of Binary Tree

难度: Easy

刷题内容

原题连接

• https://leetcode.com/problems/maximum-depth-of-binary-tree/description/

内容描述

Given a binary tree, find its maximum depth.

The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.

Note: A leaf is a node with no children.

Example:

Given binary tree [3,9,20,null,null,15,7],

    3
   / \
  9  20
    /  \
   15   7
return its depth = 3.

解题方案

思路 1 - 时间复杂度: O(N)- 空间复杂度: O(1)******

简单题,但是这道题跟leetcode111不一样，这道题没有特殊情况，所以一行就够了

class Solution(object):
    def maxDepth(self, root):
        """
        :type root: TreeNode
        :rtype: int
        """
        return 1 + max(map(self.maxDepth, (root.left, root.right))) if root else 0