Circular Queue With front and rear

RingQueue tracks front and rear instead of a size counter, which creates a problem: front == rear would mean both empty and completely full. The fix is to waste one slot on purpose - the queue calls itself full one slot early, so front == rear can only mean empty. With CAPACITY 5 that leaves room for 4 values. size() and toString() are written.

Requirements:
1. isEmpty() is true when front == rear.
2. isFull() is true when (rear + 1) % CAPACITY == front.
3. enqueue(int value): return false when full, otherwise store the value at rear, move rear forward with % CAPACITY and return true.
4. dequeue(): return -1 when empty, otherwise save items[front], move front forward with % CAPACITY and return the saved value.

Do NOT write a main method.