0104 Maximum Depth of Binary Tree.py

#https://leetcode.com/problems/maximum-depth-of-binary-tree/description/
# Definition for a binary tree node.
# class TreeNode(object):
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution(object):
    def maxDepth(self, root):
        if not root: return 0
        l = self.maxDepth(root.left)
        r = self.maxDepth(root.right)
        return max(l, r) + 1

        """
        :type root: TreeNode
        :rtype: int
        """