[Leetcode] 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.

 

Solution:

 1 /**
 2  * Definition for binary tree
 3  * public class TreeNode {
 4  *     int val;
 5  *     TreeNode left;
 6  *     TreeNode right;
 7  *     TreeNode(int x) { val = x; }
 8  * }
 9  */
10 public class Solution {
11     public boolean flag=true;
12     public boolean isBalanced(TreeNode root) {
13         getHeight(root);
14         return flag;
15     }
16     private int getHeight(TreeNode root) {
17         // TODO Auto-generated method stub
18         if(!flag)
19             return -1;
20         if(root==null)
21             return 0;
22         int lHeight=getHeight(root.left)+1;
23         int rHeight=getHeight(root.right)+1;
24         if(Math.abs(lHeight-rHeight)>1)
25             flag=false;
26         return lHeight>rHeight?lHeight:rHeight;
27     }
28 }

 

posted @ 2014-10-26 13:29  Phoebe815  阅读(167)  评论(0)  编辑  收藏  举报