Submission #1307027

#	Time	Username	Problem	Language	Result	Execution time	Memory
1307027		reginox	Star triangles (IZhO11_triangle)	C++20	100 / 100	246 ms	5856 KiB

triangle

#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define all(v) begin(v), end(v)
#define pi pair<int, int>
#define vi vector<int>
using namespace std;
const int N = 3e5+3;
int n, x[N], y[N];
map<int, int> mx, my;
int main(){
  ios_base::sync_with_stdio(0); cin.tie(0);
  cin >> n;
  for(int i = 1; i <= n; i++){
    cin >> x[i] >> y[i];
    mx[x[i]]++;
    my[y[i]]++;
  }
  ll ans = 0;
  for(int i = 1; i <= n; i++){
    ans += 1ll * (mx[x[i]] - 1) * (my[y[i]] - 1);
  }
  cout << ans;
  return 0;
}

• Subtask 1: 100 / 100