첫 번째 코드 - 정확도 통과, 효율성 통과X list 의 pop, remove은 너무 오래 걸린다. def solution(participants, completions): answer = '' for c in completions: participants.pop(participants.index(c)) return participants[0] 두 번쨰 코드 from collections import defaultdict def solution(participants, completions): answer = '' unfinished = defaultdict(int) for p in participants: unfinished[p] += 1 for c in completions: unfinished[c..