[LeetCode]题解，python：110 Balanced Binary Tree

题目来源

https://leetcode.com/problems/balanced-binary-tree/

Given a binary tree, determine if it is height-balanced.

For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees of every node never differ by more than 1.

题意分析

Input: a binary tree

Output: True or False

Conditions: 判断一颗树是不是平衡树，平衡树的意思是：对于每个节点而言，左右子树的最大深度不超过1

题目思路

递归判断。

AC代码（Python）

 1 # Definition for a binary tree node.
 2 # class TreeNode(object):
 3 #     def __init__(self, x):
 4 #         self.val = x
 5 #         self.left = None
 6 #         self.right = None
 7 
 8 class Solution(object):
 9     def Height(self, root):
10         if root == None:
11             return 0
12         return max(self.Height(root.left), self.Height(root.right)) + 1
13     def isBalanced(self, root):
14         """
15         :type root: TreeNode
16         :rtype: bool
17         """
18         if root == None:
19             return True
20         if abs(self.Height(root.left) - self.Height(root.right)) <= 1:
21             return self.isBalanced(root.left) and self.isBalanced(root.right)
22         else:
23             return False