Submission #1112593

#	Time	Username	Problem	Language	Result	Execution time	Memory
1112593		Chinguun	Star triangles (IZhO11_triangle)	C++14	100 / 100	290 ms	9244 KiB

triangle

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

const int N = 3e5 + 7;
int n, a[N], b[N], ans;
map <int, int> x, y;

signed main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);

	cin >> n;
	for (int i = 1; i <= n; i++) {
		cin >> a[i] >> b[i];
		x[a[i]]++; y[b[i]]++;
	}
	for (int i = 1; i <= n; i++) {
		ans += (x[a[i]] - 1) * (y[b[i]] - 1);
	}
	cout << ans;
	return 0;
}

• Subtask 1: 100 / 100