public class ArrayQueue2				// array implementation of queue (named ArrayQueue2 because I already have an ArrayQueue implemented)
{
	private int[] queue;				// queue is an array of ints (no Generics)
	private int front, rear, size;		// front points to the index of the current front of the queue, rear at the current rear of the queue, size is the number of elements
										//		we will use size to illustrate the problem with an array for a queue
	public ArrayQueue2()				// constructor 1:  set size to 100, initialize front, rear and size as expected
	{
		queue=new int[100];
		front=0;
		rear=-1;
		size=0;
	}
	
	public ArrayQueue2(int size)		//constructor 2:  set size to the value passed in from user class, set front, rear, size as expected
	{
		queue=new int[size];
		front=0;
		rear=-1;
		size=0;
	}
	
	public int peek() throws QueueEmptyException		// return the element at front of queue as long as rear!=-1, which would imply nothing has been enqueued yet
	{
		if(rear==-1) throw new QueueEmptyException("Queue is empty, cannot peek");
		else return queue[front];
	}

	public int dequeue() throws QueueEmptyException		// remove item at front, increment front, decrement size
	{
		if(rear==-1) throw new QueueEmptyException("Queue is empty, cannot dequeue");
		else 
		{
			int temp=queue[front];
			front++;
			size--;
			return temp;
		}
	}	
		
	public boolean isEmpty()			// queue is empty if size==0
	{
		return size==0;
	}
	
	public boolean isFull()				// queue should be full when size==queue.length, but we are using rear to indicate full, this will be explained in class
	{
		return rear==queue.length-1;
	}
	
	public void enqueue(int x) throws QueueFullException		// current rear of queue is at position rear, to enqueue, add 1 to rear first, add new element there, increment size
	{
		if(rear==queue.length-1) throw new QueueFullException("Cannot enqueue " + x + " onto full queue");
		else
		{
			rear++;
			queue[rear]=x;
			size++;
		}
	}
		
	public int getSize()			// this accessor is usually not needed, but illustrates the problem with the array queue implementation
	{								// this value may not be equal to queue.length and yet the Queue thinks its full!
		return size;
	}
}