Submission #1062554

#	Time	Username	Problem	Language	Result	Execution time	Memory
1062554		thinknoexit	Amusement Park (CEOI19_amusementpark)	C++17	42 / 100	3053 ms	227476 KiB

amusementpark

#include<bits/stdc++.h>
using namespace std;
using ll = long long;
const int MOD = 998244353;
int a[155], b[155], p[22];
map<ll, bool> ch;
int main() {
    cin.tie(nullptr)->sync_with_stdio(false);
    int n, m;
    cin >> n >> m;
    set<int> s;
    for (int i = 0;i < m;i++) {
        cin >> a[i] >> b[i];
    }
    for (int i = 1;i <= n;i++) p[i] = i;
    int ans = 0;
    do {
        int now = 0;
        ll bit = 0;
        for (int i = 0;i < m;i++) {
            if (p[a[i]] > p[b[i]]) {
                now++;
                bit ^= (1ll << i);
            }
        }
        if (!ch.count(bit)) {
            ch[bit] = 1;
            ans = (ans + now) % MOD;
        }
    } while (next_permutation(p + 1, p + 1 + n));
    cout << ans << '\n';
    return 0;
}

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