Key-Value Store with getLast

Design and implement an in-memory key-value store supporting add, get, remove, and getLast, where get does not update recency. Requirements Implement a key-value store. Required operations: get, add, remove, and getLast. Calling get(key) must not change the getLast result. Use hashmap plus linked-list style bookkeeping to support efficient lookup and last-item retrieval. Follow-up: discuss how to scale across multiple servers, including consistent hashing or partitioning. Notes Clarify whether getLast means most recently added, most recently updated, or last remaining insertion-order key. remove must update both the hashmap and linked structure.