Submission #728958

#	Time	Username	Problem	Language	Result	Execution time	Memory
728958		Rafi22	Amusement Park (CEOI19_amusementpark)	C++14	63 / 100	1784 ms	1048576 KiB

amusementpark

#include <bits/stdc++.h>

using namespace std;

#define endl '\n'
#define st first
#define nd second
#define pb push_back
#define sz(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()
#define ll long long
ll mod=998244353;
int inf=1000000007;
ll infl=1000000000000000007;

const int N=18;

unordered_map<int,int>DP[(1<<N)];
vector<int>inside[(1<<N)];
int G[N];

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int n,m,a,b;
    cin>>n>>m;
    for(int i=0;i<m;i++)
    {
        cin>>a>>b;
        a--,b--;
        G[a]^=(1<<b);
        G[b]^=(1<<a);
    }
    for(int i=0;i<(1<<n);i++)
    {
        for(int j=0;j<n;j++) if(i&(1<<j)) inside[i].pb(j);
    }
    DP[0][(1<<n)-1]=1;
    for(int a=0;a<(1<<n);a++)
    {
        int d=(1<<n)-1-a;
        for(int b=d;b>0;b=(b-1)&d)
        {
            int x=DP[a][b];
            if(x==0) continue;
            for(auto k:inside[b])
            {
                int A=a^(1<<k),B=(b&((1<<n)-(1<<(k+1))))|(G[k]&((1<<n)-1-a-(1<<k)));
                int y=DP[A][B];
                y+=x;
                if(y>=mod) y-=mod;
                DP[A][B]=y;
            }
        }
    }
    cout<<(ll)DP[(1<<n)-1][0]*(ll)m%mod*499122177%mod;
    return 0;
}

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