Submission #868102

#	Time	Username	Problem	Language	Result	Execution time	Memory
868102		12345678	Star triangles (IZhO11_triangle)	C++17	100 / 100	248 ms	12124 KiB

triangle

#include <bits/stdc++.h>

using namespace std;

long long n, ans;
map<int, int> x, y;

int main()
{
    cin.tie(NULL)->sync_with_stdio(false);
    cin>>n;
    vector<pair<int, int>> v(n);
    for (int i=0; i<n; i++) cin>>v[i].first>>v[i].second, x[v[i].first]++, y[v[i].second]++;
    for (int i=0; i<n; i++) ans+=(x[v[i].first]-1)*(y[v[i].second]-1);
    cout<<ans;
}

• Subtask 1: 100 / 100