Submission #415121

#	Time	Username	Problem	Language	Result	Execution time	Memory
415121		ngpin04	Amusement Park (CEOI19_amusementpark)	C++14	42 / 100	1976 ms	170836 KiB

amusementpark

#include <bits/stdc++.h>
#define fi first
#define se second
#define mp make_pair
using namespace std;
const int N = 1e5 + 5; 

set <long long> s;

pair <int, int> ed[N]; 

int pos[N];
int n,m;

int main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cin >> n >> m;
	for (int i = 0; i < m; i++) {
		cin >> ed[i].fi >> ed[i].se;
	}
	if (n > 10)
		return 0;

	int ans = 0;
	vector <int> id(n, 0); iota(id.begin(), id.end(), 1);
	do {
		for (int i = 0; i < n; i++) 
			pos[id[i]] = i;

		long long res = 0;
		int cnt = 0;
		for (int i = 0; i < m; i++) {
			int u = ed[i].fi;
			int v = ed[i].se;
			if (pos[u] > pos[v]) {
				cnt++;
				res |= (1LL << i);
			}
		}
		if (s.find(res) == s.end()) {
			ans += cnt;
			s.insert(res);
		}
	} while (next_permutation(id.begin(), id.end()));

	cout << ans;
	return 0;
}

• Subtask 1: 7 / 7
• Subtask 2: 12 / 12
• Subtask 3: 23 / 23
• Subtask 4: 0 / 21
• Subtask 5: 0 / 37