Design Circular Queue (Ring Buffer)

A guided phone-screen coding problem equivalent to LeetCode 622: implement a fixed-capacity circular queue. The interviewer leads you to recognize that the scenario needs a ring-buffer design, then has you implement it. Requirements Implement a fixed-capacity circular queue supporting the standard operations (enqueue, dequeue, front/rear, isEmpty, isFull). The interviewer guides you step by step until you realize a circular-buffer layout is required, then asks you to code it. Notes Equivalent to LeetCode 622 (Design Circular Queue), per the candidate's account. The signal is recognizing the ring-buffer pattern from the prompt and getting the wrap-around index arithmetic and full/empty distinction right. Preparation Implement a ring buffer with head/tail pointers and a size counter (or a reserved-empty-slot scheme) and test the wrap-around and full/empty edges.