I started with a doubly linked list plus a hash map for O(1) join, leave, and position lookup, which felt solid.
Start by clarifying requirements and constraints, then propose a class design with a doubly linked list and hash map for O(1) join/leave and O(n) ordered traversal. For top/bottom K, discuss augmenting with a balanced BST or heap, and address extensions for priorities, persistence, and concurrency with trade-offs.
Pro tip: Demonstrate awareness of real-world constraints by discussing how to handle concurrency with fine-grained locking or lock-free structures, and mention persistence options like write-ahead logging or snapshots.
Ask about expected queue size, frequency of operations, priority semantics, persistence needs, and concurrency requirements to tailor the design.
Propose a doubly linked list for O(1) insertion/removal and a hash map for O(1) access by ID, enabling ordered traversal in O(n).
Augment with a balanced BST (e.g., order-statistic tree) or a heap for O(log n) insert/delete and O(k) retrieval, discussing trade-offs.
For priorities, use a priority queue or multiple queues; for persistence, discuss logging or snapshots; for concurrency, propose locking strategies or lock-free approaches.
Summarize time and space complexities for each operation and justify design choices, acknowledging limitations and alternatives.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.