Submission #914038

#	Time	Username	Problem	Language	Result	Execution time	Memory
914038		kabgoy	Star triangles (IZhO11_triangle)	C++17	100 / 100	248 ms	6032 KiB

triangle

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

int
main(void)
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int n;
	cin >> n;
	vector<int> x(n), y(n);
	map<int,int> cntx, cnty;
	for(int i = 0; i < n; i++){
		cin >> x[i] >> y[i];
		cntx[x[i]]++;
		cnty[y[i]]++;
	}
	long long ans = 0;
	for(int i = 0; i < n; i++)
		ans += (cntx[x[i]]-1) * (long long)(cnty[y[i]]-1);
	cout << ans << '\n';
}

• Subtask 1: 100 / 100