判断是否为平衡二叉树

Posted 2020-11-27 shuangcao

题目描述

输入一棵二叉树，判断该二叉树是否是平衡二叉树。

 

在这里，我们只需要考虑其平衡性，不需要考虑其是不是排序二叉树

解法1：逐个判断每个节点

 1 # -*- coding:utf-8 -*-
 2 # class TreeNode:
 3 #     def __init__(self, x):
 4 #         self.val = x
 5 #         self.left = None
 6 #         self.right = None
 7 class Solution:
 8     def IsBalanced_Solution(self, pRoot):
 9         # write code here
10         if  not pRoot:
11             return True        
12         if abs(self.tree(pRoot.left) -self.tree(pRoot.right))>1:
13             return False
14         return self.IsBalanced_Solution(pRoot.left) and self.IsBalanced_Solution(pRoot.right)
15   
16     def tree(self,pRoot):
17         # 求深度
18         if not pRoot:
19             return 0
20         if not pRoot.left and not pRoot.right:
21             return 1
22         return max(self.tree(pRoot.left),self.tree(pRoot.right))+1
23        
24