Design an In-Memory Queue (Tradeoffs: Clearing, Background Cleanup, Stale Data)

Problem: Design an In-Memory Queue (with tradeoff discussion) Design and implement an in-memory queue supporting: enqueue(x) dequeue() (return empty/error if the queue is empty) size() After implementing the basics, discuss tradeoffs: When should the queue be cleared or memory reclaimed? Should a background thread be used for cleanup/compaction/expiration? How to avoid races with foreground operations? How do you handle stale data (e.g., TTL, slow consumers, visibility/consistency)? One possible coding I/O format Read m commands: ENQ v DEQ SIZE CLEAR Print outputs for commands that produce output. Constraints 1 <= m <= 2e5 Target amortized O(1) for operations. Example Input: 8 ENQ 1 ENQ 2 SIZE DEQ DEQ DEQ ENQ 3 SIZE Output: 2 1 2 EMPTY 1 Example Input 8 ENQ 1 ENQ 2 SIZE DEQ DEQ DEQ ENQ 3 SIZE Output 2 1 2 EMPTY 1