identical java

// http://code2begin.blogspot.com
// program to check if 2 given binary trees are identical or not

/**
 * Created by MOHIT on 25-05-2018.
 */

import java.io.*;
import java.lang.reflect.Array;
import java.util.*;

import static java.lang.Integer.max;


// node class
class node{
    int data;
    node left;
    node right;

    // function that returns a pointer to new node
    public node(int element){
        this.data = element;
        this.left = null;
        this.right = null;

    }
};


public class BinaryTree {

    // function to check if 2 given trees are identical to each other
    static boolean isIdentical(node root1, node root2){
        // if both the nodes are null then return true
        if (root1 == null && root2 == null){
            return true;
        }

        // if the node are not null then check
        // 1. do nodes have same data
        // 2. do the have identical left subtrees
        // 3. do the have identical right subtrees
        if (root1 != null && root2 != null){
            return (
                root1.data == root2.data &&
                isIdentical(root1.left, root2.left) &&
                isIdentical(root1.right, root2.right)
            );
        }
        return false;
    }


    public static void main(String arg[]) {
        node head = new node(1);
        head.left = new node(2);
        head.right = new node(3);
        head.left.left = new node(4);
        head.left.right = new node(5);
        head.right.right = new node(6);
        head.left.left.right = new node(7);
        head.right.right.left = new node(8);
        head.left.left.right.left = new node(9);
        head.left.left.right.left.left = new node(10);
        head.right.right.left.right = new node(11);

        node head2 = new node(5);
        head2.left = new node(2);
        head2.right = new node(12);
        head2.left.left = new node(-4);
        head2.left.right = new node(3);
        head2.right.left = new node(9);
        head2.right.right = new node(21);
        head2.right.right.left = new node(19);
        head2.right.right.right = new node(25);

        node head3 = new node(1);
        head3.left = new node(2);
        head3.right = new node(3);
        head3.left.left = new node(4);
        head3.left.right = new node(5);
        head3.right.right = new node(6);
        head3.left.left.right = new node(7);
        head3.right.right.left = new node(8);
        head3.left.left.right.left = new node(9);
        head3.left.left.right.left.left = new node(10);
        head3.right.right.left.right = new node(11);

        System.out.println("TREE #1 and TREE #2 are identical : " + isIdentical(head, head2));
        System.out.println("TREE #1 and TREE #3 are identical : " + isIdentical(head, head3));

    }
}