Submission #89293

#	Time	Username	Problem	Language	Result	Execution time	Memory
89293		Erkhemkhuu	Star triangles (IZhO11_triangle)	C++17	100 / 100	932 ms	38552 KiB

triangle

#include <bits/stdc++.h>
using namespace std;
int x[300005], y[300005];
map <int, int> cntx, cnty;
int main() {
	int n, i, ans;
	cin >> n;
	for(i = 0; i < n; i++) {
		cin >> x[i] >> y[i];
		cntx[x[i]]++;
		cnty[y[i]]++;
	}
	ans = 0;
	for(i = 0; i < n; i++)
		ans += (cntx[x[i]] - 1) * (cnty[y[i]] - 1);
	cout << ans << "\n";
	return 0;
}

• Subtask 1: 100 / 100