Interview guides / ios

LRU cache: iOS Interview Question

LRU cache interview question with a clear example answer for iOS engineers. Practice with AceMobileInterview.

This is a common iOS interview topic: LRU cache.

Below is a concise answer you can adapt in a real interview, then go deeper in the full AceMobileInterview track.

1. 1.Design an LRU cache with O(1) get and put. What data structures would you use in Swift?

   Dictionary for key → node plus a doubly linked list (or ordered dictionary pattern) for recency. On get/put, move node to head; on capacity overflow, evict tail. Clarify thread safety if asked—actors or locks around the structure.