import java.util.LinkedList;
import java.util.Queue;

/*
 *  Example of remove() and poll() methods.
 */
public class QueueExample
{

    public static void main( String[] args )
    {
        Queue<Integer> queue = new LinkedList<Integer>();
        queue.add(200);
        queue.add(300);
        queue.add(400);
        queue.add(500);

        System.out.println("queue : " + queue + "\n");

        /*
         * Retrieves and removes the head of this queue. This method differs
         * from poll only in that it throws an exception if this queue is empty.
         */
        Integer removedElement = queue.remove();

        System.out.println("removedElement : " + removedElement);
        System.out.println("queue : " + queue + "\n");

        /*
         * Retrieves and removes the head of this queue, or returns null if this
         * queue is empty.
         */
        removedElement = queue.poll();
        System.out.println("removedElement : " + removedElement);
        System.out.println("queue : " + queue + "\n");

    }
}