Submission #331104

#	Time	Username	Problem	Language	Result	Execution time	Memory
331104		AlexLuchianov	Star triangles (IZhO11_triangle)	C++14	100 / 100	363 ms	5868 KiB

triangle

#include <iostream>
#include <vector>
#include <map>

using ll = long long;
#define MIN(a, b) (((a) < (b)) ? (a) : (b))
#define MAX(a, b) (((a) < (b)) ? (b) : (a))

std::map<int,int> frecx, frecy;

int const nmax = 300000;
int v[1 + nmax][2];

int main() {
  std::ios::sync_with_stdio(0);
  std::cin.tie(0);

  int n;
  std::cin >> n;
  for(int i = 1;i <= n; i++)
    std::cin >> v[i][0] >> v[i][1];
  for(int i = 1;i <= n; i++) {
    frecx[v[i][0]]++;
    frecy[v[i][1]]++;
  }
  ll result = 0;
  for(int i = 1;i <= n; i++)
    result += 1LL * (frecx[v[i][0]] - 1) * (frecy[v[i][1]] - 1);
  std::cout << result;
}

• Subtask 1: 100 / 100