Submission #531725

#	Time	Username	Problem	Language	Result	Execution time	Memory
531725		kebine	Star triangles (IZhO11_triangle)	C++17	100 / 100	691 ms	11988 KiB

triangle

#include <bits/stdc++.h>
using namespace std;
#define ll long long
int n;
pair<int, int> star[300005];
map<int, int> x, y;


int main() {
  cin >> n;
  for(int i = 0; i < n; i++) {
    cin >> star[i].first >> star[i].second;
    //cout << star[i].first << " " << star[i].second << endl;
    if(x.count(star[i].first) > 0) {
      int now = x.find(star[i].first) -> second;
      x.erase(star[i].first);
      x.insert({star[i].first, now + 1});
      //cout << "x" << now << endl;
    }
    else {
      x.insert({star[i].first, 1});
    }
    if(y.count(star[i].second) > 0) {
      int now = y.find(star[i].second) -> second;
      y.erase(star[i].second);
      y.insert({star[i].second, now + 1});
      //cout << "y" << now << endl;
    }
    else {
      y.insert({star[i].second, 1});
    }
  }
  
  ll ans = 0;
  
  for(int i = 0; i < n; i++) {
    int hor = x.find(star[i].first) -> second;
    hor--;
    int ver = y.find(star[i].second) -> second;
    ver--;
    ans += 1ll * ver * hor;
    
  }
  cout << ans << endl;
}

• Subtask 1: 100 / 100