/**
 * My Data Structures demo of an array-based, bounded Queue implementation.
 */
public class DSArrayBoundedQueue<T> implements DSQueueInterface<T>
{
  protected final int DEFCAP = 100;
  protected T[] elements;
  protected int numElements = 0;
  protected int front = 0;
  protected int rear;
  
  public DSArrayBoundedQueue()
  {
    elements = (T[]) new Object[DEFCAP];
    rear = DEFCAP - 1;
  }
  
  public DSArrayBoundedQueue(int size)
  {
    elements = (T[]) new Object[size];
    rear = size - 1;
  }
  
  public void enqueue(T element)
  {
    if (isFull())
      throw new DSQueueOverflowException("Enqueue attempted on a full queue!");
    else
    {
      rear = (rear + 1) % elements.length;
      elements[rear] = element;
      numElements++;
    }
  }
  
  public T dequeue()
  {
    if (isEmpty())
      throw new DSQueueUnderflowException("Dequeue attempted on empty space!");
    else
    {
      T toReturn = elements[front];
      elements[front] = null;
      front = (front + 1) % elements.length;
      numElements--;
      return toReturn;
    }
  }
  
  public boolean isFull()
  {
    return (numElements == elements.length);
  }
  
  public boolean isEmpty()
  {
    return (numElements == 0);
  }
  
  public int size()
  {
    return numElements;
  }
}