Submission #976054

#	Time	Username	Problem	Language	Result	Execution time	Memory
976054		vjudge1	Star triangles (IZhO11_triangle)	C++17	100 / 100	374 ms	5820 KiB

triangle

#include <bits/stdc++.h>
using namespace std;

const int kaps = 3e5 + 5;

int main(){
    long long n;
    cin >> n;
    int x[kaps], y[kaps];
    int ans = 0;
    map <int, int> jx;
    map <int, int> jy;
    for(int i = 0; i < n; i++){
        cin >> x[i] >> y[i];
        jx[x[i]]++;
        jy[y[i]]++;
    }for(int i = 0; i < n; i++){
        ans += (jx[x[i]] - 1) * (jy[y[i]] - 1);
    }cout << ans << endl;
}

• Subtask 1: 100 / 100