Submission #532100

#	Time	Username	Problem	Language	Result	Execution time	Memory
532100		kebine	Star triangles (IZhO11_triangle)	C++17	0 / 100	1 ms	296 KiB

triangle

#include <bits/stdc++.h>
#define pb push_back
#define fi first
#define se second
typedef long long ll;
using namespace std;

ll n, ans;
pair<ll,ll>arr[300005];
ll total[300005];

int main(){
  cin >> n;
  for(int i = 0; i < n; i++){
    cin >> arr[i].fi >> arr[i].se;
    total[arr[i].se]++;
  }
  for(int i = 0; i < n; i++){
    for(int j = 0; j < n; j++){
      if(i==j || arr[i].fi != arr[j].fi)continue;
      ans += total[arr[j].se]-1;
//      cout << total[arr[j].se] << endl;
//      cout << arr[i].fi << " " << arr[i].se << " : " << arr[j].fi << " " << arr[j].se << " : " << ans << endl;
    }
  }
  cout << ans << endl;
}

//tle lmao

• Subtask 1: 0 / 100