Question

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.

Use following Node class, no height is stored in the Node

/**

* Definition for a binary tree node. *

public class TreeNode

{

* int val;

* TreeNode left;

* TreeNode right;

* TreeNode(int x) { val = x; }

* }

*/ class Solution

{

public boolean isBalanced(TreeNode root)

{ }

}

Answer 1

public class TreeNode {
   int val;
   TreeNode left;
   TreeNode right;

   TreeNode(int x) {
       val = x;
   }
}

class Solution {

   public boolean isBalanced(TreeNode root) {
       // left tree height
       int lh;
       // right tree height
       int rh;
       // if tree is empty returning true
       if (root == null)
           return true;
       // getting the heght of left and right
       lh = getHeight(root.left);
       rh = getHeight(root.right);
      
       // checking if the difference is -1 or 1 or 0
       if (Math.abs(lh - rh) <= 1 && isBalanced(root.left) && isBalanced(root.right))
           return true;

       return false;
   }
   // returns the height of tree
   int getHeight(TreeNode node) {
       if (node == null)
           return 0;
       return 1 + Math.max(getHeight(node.left), getHeight(node.right));
   }
}