I started with the read/write pointer approach and it went fine until they asked about the full vs empty state distinction.
Start by clarifying requirements (fixed-size, thread-safety, overwrite behavior) and then design a ring buffer using a fixed-size array with head and tail indices. Implement core operations (write, read, isFull, isEmpty) with careful handling of wrap-around and edge cases, then discuss trade-offs and potential optimizations.
Pro tip: Mention thread-safety early: even if not required, discussing lock-free or mutex-based approaches shows you think about production use. Also, explicitly handle the full vs. empty ambiguity by either keeping a count or sacrificing one slot.
Ask about buffer size (fixed or dynamic), overwrite policy when full, thread-safety needs, and expected operations (read, write, peek, etc.).
Choose a fixed-size array with head and tail indices. Decide how to track size (count variable or leave one slot empty) to distinguish full vs. empty.
Write methods for write (enqueue), read (dequeue), isEmpty, isFull, and optionally size. Use modulo arithmetic for wrap-around and handle edge cases.
Walk through examples: filling buffer, wrapping around, reading when empty, writing when full. Check boundary conditions like size 0 or 1.
Talk about time/space complexity, thread-safety options (locks, atomics), and alternatives like linked-list-based buffers or dynamic resizing.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.