[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:

/**
 * Definition for binary tree
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
public class Solution {
    public boolean flag=true;
    public boolean isBalanced(TreeNode root) {
        getHeight(root);
        return flag;
    }
    private int getHeight(TreeNode root) {
        // TODO Auto-generated method stub
        if(!flag)
            return -1;
        if(root==null)
            return 0;
        int lHeight=getHeight(root.left)+1;
        int rHeight=getHeight(root.right)+1;
        if(Math.abs(lHeight-rHeight)>1)
            flag=false;
        return lHeight>rHeight?lHeight:rHeight;
    }
}