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 everynode 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 int Depth(TreeNode root){
12         if(root == null)
13             return 0;
14         return 1 + Math.max(Depth(root.left), Depth(root.right));
15     }
16     public boolean isBalanced(TreeNode root) {
17         // Start typing your Java solution below
18         // DO NOT write main() function
19         if(root == null) return true;
20         int leftDepth = Depth(root.left);
21         int rightDepth = Depth(root.right);
22         if(Math.abs(leftDepth - rightDepth) > 1)
23             return false;
24         else
25             return isBalanced(root.left) && isBalanced(root.right);
26     }
27 }

 

posted @ 2013-01-27 11:56  cradle  阅读(251)  评论(0)  编辑  收藏  举报