- 分类：Tree/BackTracking
- 时间复杂度: O(n) 这种把树的节点都遍历一遍的情况时间复杂度为O(n)
- 空间复杂度: O(h) 树的节点的深度
104. Maximum Depth of Binary Tree
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.
代码：
# Definition for a binary tree node.
# class TreeNode:
# def __init__(self, x):
# self.val = x
# self.left = None
# self.right = None
class Solution:
def maxDepth(self, root: 'TreeNode') -> 'int':
if root==None:
return 0
res=max(self.maxDepth(root.left),self.maxDepth(root.right))+1
return res
讨论：
1.这道题是道简单的好题，思路就是现在的深度为左边和右边深度的最大值再加上+1
