Submission #1033417

#	Time	Username	Problem	Language	Result	Execution time	Memory
1033417		codefox	Amusement Park (CEOI19_amusementpark)	C++14	0 / 100	0 ms	348 KiB

amusementpark

#include <bits/stdc++.h>

using namespace std;

#pragma GCC target("popcnt")
#pragma GCC optimize("Ofast")

#define int long long
#define pii pair<int, int>

const int mod = 998244353;

int32_t main()
{
    int n, m;
    cin >> n >> m;
    vector<bitset<20>> graph(n, 0);
    vector<bitset<20>> dgraph(n, 0);
    for (int i = 0; i < m; i++)
    {
        int a, b;
        cin >> a >> b;
        a--; b--;
        graph[a][b] = 1;
        dgraph[a][b] = 1;
        dgraph[b][a] = 1;
    }
    int N = 1<<n;
    vector<pii> dp(N, {0,0});
    dp[0] = {1, 0};
    for (int i = 0; i < N; i++)
    {
        for (int j = 0; j < n; j++)
        {
            if (i&(1<<j)) continue;
            int b = 0;
            for (int k = 0; k < j; k++)
            {
                if (!dgraph[k][j]) b = 1;
            }
            if (b) continue;
            int d = (graph[j]&(bitset<20>(i))).count();
            dp[i+(1<<j)].first += dp[i].first;
            dp[i+(1<<j)].first%=mod;
            dp[i+(1<<j)].second += dp[i].second+dp[i].first*d;
            dp[i+(1<<j)].second%=mod;
        }
    }
    cout << dp[N-1].second;
    return 0;
}

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