프로그래머스 - 혼자 놀기의 달인 (L2)

 1def solution(cards):
 2    length = len(cards)
 3    visited = [False] * length
 4    answer = []
 5    
 6    for i in range(length):
 7        cnt = 0
 8        cur = i
 9        while not visited[cur-1]:
10            visited[cur-1] = True
11            cur = cards[cur-1]
12            cnt += 1
13        if cnt != 0:
14            answer.append(cnt)
15    
16    if len(answer) <= 1:
17        return 0
18    answer.sort(reverse=True)
19    return answer[0]*answer[1]