[LeetCode]Balanced Binary Tree

标签：java   leetcode   depth-first search   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.

/**
 * Definition for binary tree
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
public class Solution {
    public boolean isBalanced(TreeNode root) {
        if(root==null) return true;
        if(depth(root)!=-1) return true;
        return false;
    }
    
    private int depth (TreeNode root){
    	if(root==null) return 0;
    	int left = 0;
    	int right = 0;
    	if(root.left!=null) {
    		left = depth(root.left);
    	}
    	if(root.right!=null) {
    		right = depth(root.right);
    	}
    	if(left<0||right<0||Math.abs(right-left)>1) return -1;
    	return Math.max(depth(root.left),depth(root.right))+1;
    }
}

[LeetCode]Balanced Binary Tree

标签：java   leetcode   depth-first search   tree   

原文地址：http://blog.csdn.net/guorudi/article/details/41518293