balanced binary tree(判断是否是平衡二叉树)

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.

在求高度的过程中判断是否为平衡树。。

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
class Solution {
    boolean flag=true;
    public boolean isBalanced(TreeNode root) {
        Depth(root);
        return flag;
    }

    //求高度，在此过程中判断是否平衡。
    public int Depth(TreeNode node){
        if(node==null) return 0;
        int left=Depth(node.left);
        int right=Depth(node.right);
        if(Math.abs(left-right)>1)
            flag=false;
        return Math.max(left,right)+1;
    }
}