平衡二叉树

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。

 1 public class Solution {
 2     boolean flag = true;
 3     public boolean IsBalanced_Solution(TreeNode root) {
 4         if(root == null) return true;
 5           
 6         getDepth(root);
 7             
 8         return flag;
 9     }
10     
11     public int getDepth(TreeNode root){
12         if(root == null) return 0;
13         int left = getDepth(root.left);
14         int right = getDepth(root.right);
15         int len = left - right;
16         
17         if(Math.abs(len) > 1) flag = false;
18         
19          return left > right ? left + 1 : right + 1;  
20     }
21 }