public class Queue_ArrayBased implements IQueue, IArrayBased {
	int size;
    Object []array;
	public Queue_ArrayBased(int size) {
		this.size = size;
	 array = new Object[size];
	}
	int f = 0, r = 0;

	public void enqueue(Object item) {
		if (size() == size)
			throw new RuntimeException();
		array[r] = item;
		r = (r + 1) % size;

	}

	public Object dequeue() {
		if (isEmpty())
			throw new RuntimeException();
		Object getter = array[f];
		array[f] = null;
		f = (f + 1) % size;
		return getter;
	}

	public boolean isEmpty() {

		return (f == 0 && r == 0);
	}

	public int size() {

		return (size - f + r) % size;
	}

}