Level order traversal Line by Line Java

PROGRAM TO PRINT LEVEL ORDER TRAVERSAL LINE BY LINE

import java.util.LinkedList;

import java.util.Queue;

  

public class LevelOrder 

{

    // A Binary Tree Node

    static class Node

    {

        int data;

        Node left;

        Node right;

          

        // constructor

        Node(int data){

            this.data = data;

            left = null;

            right =null;

        }

    }

      

    // Iterative method to do level order traversal line by line

    static void printLevelOrder(Node root)

    {

        // Base Case

        if(root == null)

            return;

          

        // Create an empty queue for level order tarversal

        Queue<Node> q =new LinkedList<Node>();

          

        // Enqueue Root and initialize height

        q.add(root);

          

          

        while(true)

        {

              

            // nodeCount (queue size) indicates number of nodes

            // at current level.

            int nodeCount = q.size();

            if(nodeCount == 0)

                break;

              

            // Dequeue all nodes of current level and Enqueue all

            // nodes of next level

            while(nodeCount > 0)

            {

                Node node = q.peek();

                System.out.print(node.data + " ");

                q.remove();

                if(node.left != null)

                    q.add(node.left);

                if(node.right != null)

                    q.add(node.right);

                nodeCount--;

            }

            System.out.println();

        }

    }

      

    // Driver program to test above functions

    public static void main(String[] args) 

    {

        // Let us create binary tree shown in above diagram

       /*               1

                   /     \

                  2       3

                /   \       \

               4     5       6

        */

          

        Node root = new Node(1);

        root.left = new Node(2);

        root.right = new Node(3);

        root.left.left = new Node(4);

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

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

          

        printLevelOrder(root);

  

    }

  

}




OUTPUT:

1
2 3
4 5 6

CREDITS: https://www.geeksforgeeks.org/print-level-order-traversal-line-line/