[Algorithm] Programmers :: 혼자 놀기의 달인

https://school.programmers.co.kr/learn/courses/30/lessons/131130

프로그래머스

bool visited[101] = { false };
vector<int> answers;
 
void DFS(int boxNum, int groupNum, int count, vector<int>& cards)
{
    if (visited[boxNum])
    {
        answers.push_back(count);
        return;
    }
 
    visited[boxNum] = true;
    DFS(cards[boxNum]-1, groupNum, count+1, cards);
}
 
int solution(vector<int> cards) 
{
    int groupNum = -1;
 
    for (int i = 0; i < cards.size(); ++i)
    {
        if (visited[i]) continue;
        ++groupNum;
 
        visited[i] = true;
        DFS(cards[i]-1, groupNum, 1, cards);
    }
 
    if (answers.size() == 1) return 0;
 
    sort(answers.rbegin(), answers.rend());
 
    return answers[0] * answers[1];
}