leetcode - 104 - 二叉树的最大深度

# 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):
        """
        :type root: TreeNode
        :rtype: int
        """
        #递归
        if root is None:
            return 0
        left_height = self.maxDepth(root.left)
        right_height = self.maxDepth(root.right)
        
        return max(left_height,right_height)+1