Connect Nodes at Same Level Java

PROGRAM TO CONECT NODES AT SAME LEVEL

class Node {

    int data;

    Node left, right, nextRight;

  

    Node(int item)

    {

        data = item;

        left = right = nextRight = null;

    }

}

  

class BinaryTree {

    Node root;

  

    // Sets the nextRight of root and calls connectRecur()

    // for other nodes

    void connect(Node p)

    {

  

        // Set the nextRight for root

        p.nextRight = null;

  

        // Set the next right for rest of the nodes (other

        // than root)

        connectRecur(p);

    }

  

    /* Set next right of all descendents of p.

       Assumption:  p is a compete binary tree */

    void connectRecur(Node p)

    {

        // Base case

        if (p == null)

            return;

  

        // Set the nextRight pointer for p's left child

        if (p.left != null)

            p.left.nextRight = p.right;

  

        // Set the nextRight pointer for p's right child

        // p->nextRight will be NULL if p is the right most child

        // at its level

        if (p.right != null)

            p.right.nextRight = (p.nextRight != null) ? p.nextRight.left : null;

  

        // Set nextRight for other nodes in pre order fashion

        connectRecur(p.left);

        connectRecur(p.right);

    }

  

    // Driver program to test above functions

    public static void main(String args[])

    {

        BinaryTree tree = new BinaryTree();

  

        /* Constructed binary tree is

             10

            /  \

          8     2

         /

        3

        */

        tree.root = new Node(10);

        tree.root.left = new Node(8);

        tree.root.right = new Node(2);

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

  

        // Populates nextRight pointer in all nodes

        tree.connect(tree.root);

  

        // Let us check the values of nextRight pointers

        System.out.println("Following are populated nextRight pointers in "

                           + "the tree"

                           + "(-1 is printed if there is no nextRight)");

        int a = tree.root.nextRight != null ? tree.root.nextRight.data : -1;

        System.out.println("nextRight of " + tree.root.data + " is "

                           + a);

        int b = tree.root.left.nextRight != null ? tree.root.left.nextRight.data : -1;

        System.out.println("nextRight of " + tree.root.left.data + " is "

                           + b);

        int c = tree.root.right.nextRight != null ? tree.root.right.nextRight.data : -1;

        System.out.println("nextRight of " + tree.root.right.data + " is "

                           + c);

        int d = tree.root.left.left.nextRight != null ? tree.root.left.left.nextRight.data : -1;

        System.out.println("nextRight of " + tree.root.left.left.data + " is "

                           + d);

    }

}




OUTPUT:

Following are populated nextRight pointers in the tree (-1 is printed if there is no nextRight)
nextRight of 10 is -1
nextRight of 8 is 2
nextRight of 2 is -1
nextRight of 3 is -1

CREDITS: https://www.geeksforgeeks.org/connect-nodes-at-same-level/