Submission #928216

#	Time	Username	Problem	Language	Result	Execution time	Memory
928216		vjudge1	Amusement Park (CEOI19_amusementpark)	C++17	0 / 100	0 ms	348 KiB

amusementpark

#include<bits/stdc++.h>

using namespace std;

#define F first
#define S second
#define ll long long
#define maksim gay
#define int ll
#define pb push_back
#define sz(s) (int)s.size()
#define pii pair<int,int>
#define all(v) v.begin(),v.end()
#define mem(a,i) memset(a,i,sizeof(a))
#define in insert
#define lb lower_bound
#define ub upper_bound

const int MAX=20;
const int inf=1e10;
const int N=2e5;

int n,m;
int d[MAX][MAX];

void solve(){
  cin>>n>>m;
  vector<int> v;
  for(int i=1;i<=n;i++)v.pb(i);
  for(int i=1;i<=m;i++){
    int a,b;
    cin>>a>>b;
    d[a][b]=1;
  }
  int ans=0;
  do{
    for(int i=0;i<n;i++){
      for(int j=0;j<i;j++){
        if(d[v[i]][v[j]])ans++;
      }
    }
  }while(next_permutation(all(v)));
  cout<<ans<<"\n";
}


main(){
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int t=1;
  // cin>>t;
  while(t--){
    solve();
  }
}

Compilation message (stderr)

amusementpark.cpp:47:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   47 | main(){
      | ^~~~

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