효율적인 해킹

#include <iostream> #include <vector> #include <utility> using namespace std; int result; int answer = 0; vector<bool> visited; vector<vector<int> > computer; void dfs(int computerNumber, int depth) { if (computer[computerNumber].size() == 0 || visited[computerNumber]) { result = depth; if (depth > answer) answer = depth; return ; } visited[computerNumber] = true; for (unsigned int i = 0; i < computer[computerNumber].size(); i++) { dfs(computer[computerNumber][i], depth + 1); visited[computer[computerNumber][i]] = false; } } int main(void) { int n,m; vector<int> computerList; int a, b; int depth; ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0); cin >> n >> m; computer.resize(n + 1); visited.resize(n + 1); computerList.resize(n + 1); for (int i = 0; i < m; i++) { cin >> a >> b; computer[b].push_back(a); } for (int i = 1; i <= n; i++) { fill(visited.begin(), visited.end(), false); depth = 0; dfs(i, depth + 1); computerList[i] = result; } for (int i = 1; i <= n; i++) if (computerList[i] == answer) cout << i << " "; return (0); }