牛客网每日一练

# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

#
# 
# @param root TreeNode类 
# @return int整型
#
class Solution:
    def maxDepth(self , root ):
        left_depth = 0
        right_depth = 0
        depth = 0
        if root is None:
            return depth
        if root.right is not None:
            right_depth += self.maxDepth(root.right)
        if root.left is not None:
            left_depth += self.maxDepth(root.left)
        if root.left is None and root.right is None:
            return 1
        if left_depth > right_depth:
            depth += left_depth
        else:
            depth += right_depth
        return depth + 1

求给定二叉树的最大深度

此题是典型的深度优先搜索题，我是用python3具体实现