Check for Balanced Tree Java

PROGRAM TO DETERMINE IF A BINARY TREE IS HEIGHT BALANCED

class Node {

  

    int data;

    Node left, right;

  

    Node(int d)

    {

        data = d;

        left = right = null;

    }

}

  

// A wrapper class used to modify height across

// recursive calls.

class Height {

    int height = 0;

}

  

class BinaryTree {

  

    Node root;

  

    /* Returns true if binary tree with root as root is height-balanced */

    boolean isBalanced(Node root, Height height)

    {

        /* If tree is empty then return true */

        if (root == null) {

            height.height = 0;

            return true;

        }

  

        /* Get heights of left and right sub trees */

        Height lheight = new Height(), rheight = new Height();

        boolean l = isBalanced(root.left, lheight);

        boolean r = isBalanced(root.right, rheight);

        int lh = lheight.height, rh = rheight.height;

  

        /* Height of current node is max of heights of

           left and right subtrees plus 1*/

        height.height = (lh > rh ? lh : rh) + 1;

  

        /* If difference between heights of left and right

           subtrees is more than 2 then this node is not balanced

           so return 0 */

        if (Math.abs(lh - rh) >= 2)

            return false;

  

        /* If this node is balanced and left and right subtrees

           are balanced then return true */

        else

            return l && r;

    }

  

    public static void main(String args[])

    {

        Height height = new Height();

  

        /* Constructed binary tree is

                   1

                 /   \

                2      3

              /  \    /

            4     5  6

            /

           7         */

        BinaryTree tree = new BinaryTree();

        tree.root = new Node(1);

        tree.root.left = new Node(2);

        tree.root.right = new Node(3);

        tree.root.left.left = new Node(4);

        tree.root.left.right = new Node(5);

        tree.root.right.right = new Node(6);

        tree.root.left.left.left = new Node(7);

  

        if (tree.isBalanced(tree.root, height))

            System.out.println("Tree is balanced");

        else

            System.out.println("Tree is not balanced");

    }

}




OUTPUT:

Tree is balanced

CREDITS: https://www.geeksforgeeks.org/how-to-determine-if-a-binary-tree-is-balanced/