Problem Balanced Binary Tree

 1     public boolean isBalanced(TreeNode root) {
 2         int[] height = new int[1];
 3         return isBalancedWithHeight(root, height);
 4     }
 5     
 6     public boolean isBalancedWithHeight(TreeNode root, int[] height) {
 7 int[] lh = new int[1];
 8         int[] rh = new int[1];
 9         boolean l,r;
10 
11         if (root == null) {
12             height[0] = 0;
13             return true;
14         }
15 
16         l = isBalancedWithHeight(root.left, lh);
17         r = isBalancedWithHeight(root.right, rh);
18 
19         height[0] = ((lh[0] > rh[0])? lh[0] : rh[0]) + 1;
20 
21         return (Math.abs(lh[0]-rh[0]) < 2) && l && r;
22     }