Submission #532123

#	Time	Username	Problem	Language	Result	Execution time	Memory
532123		kebine	Star triangles (IZhO11_triangle)	C++17	100 / 100	516 ms	14748 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];
map<ll,ll>x,y;

int main(){
  cin >> n;
  
  for(int i = 0; i < n; i++){
    cin >> arr[i].fi >> arr[i].se;
    x[arr[i].fi]++;
    y[arr[i].se]++;
  }
  for(int i = 0; i < n; i++){
    ans += (x[arr[i].fi]-1) * (y[arr[i].se]-1);
  }
  cout << ans << endl;
}

• Subtask 1: 100 / 100