//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//Queue Class
//Description: Implements a Queue Abstract Data Type using a Linked List
//	for internal storage.
//CS 284
//Programmed by Jonathan Voris
//2/28/06
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
import java.util.LinkedList;

public class Queue
{
	private LinkedList items;

	//no-argument constructor initializes the linked list
	public Queue()
	{
		items = new LinkedList();
	}

	public Object insert(Object item)
	{
		items.add(item);
		return item;
	}

	public Object peek()
	{
		if (items.size() == 0)
		{//throw an exception if the queue is peeked at while empty
			throw new EmptyQueueException();
		}

		return items.getFirst();
	}

	public Object remove()
	{
		if (items.size() == 0)
		{//throw an exception if a remove is attempted while the queue is empty
			throw new EmptyQueueException();
		}

		return items.removeFirst();
	}

	public int getSize()
	{
		return items.size();
	}

	public boolean isEmpty()
	{
		if (getSize() == 0)
		{
			return true;
		}
		else
		{
			return false;
		}
	}

}