Submission #91685

#	Time	Username	Problem	Language	Result	Execution time	Memory
91685		SamAnd	Star triangles (IZhO11_triangle)	C++17	100 / 100	672 ms	12408 KiB

triangle

#include <bits/stdc++.h>
using namespace std;
#define m_p make_pair
const int N = 300005;

int n;
pair<int, int> a[N];

map<int, int> x, y;

int main()
{
    cin >> n;
    for (int i = 0; i < n; ++i)
    {
        cin >> a[i].first >> a[i].second;
        x[a[i].first]++;
        y[a[i].second]++;
    }
    long long ans = 0;
    for (int i = 0; i < n; ++i)
    {
        ans += ((x[a[i].first] - 1LL) * (y[a[i].second] - 1LL));
    }
    cout << ans << endl;
    return 0;
}

• Subtask 1: 100 / 100