Submission #945642

#	Time	Username	Problem	Language	Result	Execution time	Memory
945642		vjudge1	Amusement Park (CEOI19_amusementpark)	C++17	19 / 100	3034 ms	600 KiB

amusementpark

#include <bits/stdc++.h>
#define int long long
#define all(x) x.begin(),x.end()
#define ff first
#define ss second
#define pb push_back
using namespace std;
vector <int> g[20];
int cl[20];
bool ok=1;
void dfs(int v){
    cl[v]=1;
    for(auto to : g[v]){
        if(cl[to]==0)dfs(to);
        else if(cl[to]==1)ok=0;
    }
    cl[v]=2;
}
signed main(){
    int n,m;
    cin>>n>>m;
    vector <int> u(m),v(m);
    for(int i=0;i<m;i++){
        cin>>u[i]>>v[i];
    }
    int ans=0;
    for(int i=0;i<(1<<m);i++){
        for(int j=1;j<=n;j++){
            cl[j]=0;
            g[j].clear();
        }
        ok=1;
        int cnt=0;
        for(int j=0;j<m;j++){
            if((i & (1<<j))){
                g[v[j]].pb(u[j]);cnt++;
            }
            else g[u[j]].pb(v[j]);
        }
        for(int j=1;j<=n;j++){
            if(!cl[j])dfs(j);
        }
        if(ok)ans+=cnt;
    }
    cout<<ans<<"\n";
}


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