Leetcode 104 Maximum Depth of Binary Tree python

題目：

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.

 求二叉樹的深度，遞歸一下就可以求到了。

python新手(我)發現python中沒有三元運算符，不過可以用true_part if condition else false_part模擬。雖然我後面用max函數代替了三元運算符，也實現了功能。

1 class Solution(object):
2     def maxDepth(self, root):
3         if (root == None):
4             return 0
5         left_depth = self.maxDepth(root.left)
6         right_depth = self.maxDepth(root.right)
7         return max(left_depth, right_depth) + 1