Implement LRU cache with O(1) ops
Company: Amazon
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: Medium
Interview Round: Onsite
Design and implement a fixed-capacity cache supporting get(key) -> value and put(key, value) in O(
1) average time. When capacity is reached, evict the least recently used entry. Specify how recency is updated on get and put, how updates to existing keys are handled, what to return for missing keys, and discuss thread-safety options and testing strategy.
Quick Answer: This question evaluates proficiency in cache design and efficient data structures, covering LRU eviction semantics, O(1) average-time get/put operations, update and missing-key behavior, concurrency/thread-safety considerations, and testing strategy within the Coding & Algorithms domain.
