Question
A podcast app logs every episode play in one session as a list of episode ids, in play order. An analyst wants the episode that was played exactly k times; if several episodes tie, they want the one whose first play happened earliest in the session. Given the log and an integer k (k >= 1), return that episode id, or an empty string when no episode was played exactly k times. For example, with log ["e1","e2","e1","e3","e2","e1"] and k = 2, episode "e2" is the answer.
first_exactly_k(episodes: list[str], k: int) → str[["e1","e2","e1","e3","e2","e1"],2]out"e2"State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.
Vibe coding: describe the solution in plain language (or narrate it) and the coach grades your approach. Generating runnable code from your description is coming next.