Submission #293864

#	Time	Username	Problem	Language	Result	Execution time	Memory
293864		7_7_7	Star triangles (IZhO11_triangle)	C++17	100 / 100	510 ms	12408 KiB

triangle

#include <bits/stdc++.h>

using namespace std;

int n;
map<int, int> x;
map<int, int> y;
int main()
{
    ios_base::sync_with_stdio(false);

    cin >> n;
    vector<int> a(n + 1), b(n + 1);
    for(int i = 1; i <= n; i ++){
        cin >> a[i] >> b[i];
        x[a[i]] ++; y[b[i]] ++;
    }
    long long res = 0;
    for(int i = 1; i <= n; i ++){
        x[a[i]] --; y[b[i]] --;
        res += (x[a[i]] * 1ll * y[b[i]]);
        x[a[i]] ++; y[b[i]] ++;
    }
    cout << res << "\n";
}

• Subtask 1: 100 / 100