[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].java

/**
 * 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) {
        // Start typing your Java solution below
        // DO NOT write main() function
        if(check(root) == -1) return false;
        else return true;
    }
    
    public int check(TreeNode root){
        if(root == null) return 0;
        int left = check(root.left);
        int right = check(root.right);
        if(left == -1 || right == -1) return -1;
        if(Math.abs(left - right) > 1) return -1;
        return Math.max(left, right) + 1;
        
    }
}