Submission #1044294

#	Time	Username	Problem	Language	Result	Execution time	Memory
1044294		EntityPlantt	Star triangles (IZhO11_triangle)	C++17	100 / 100	72 ms	11980 KiB

triangle

#include <iostream>
#include <unordered_map>
using namespace std;

const int N = 3e5 + 5;
pair <int, int> s[N];
unordered_map <int, int> mx, my;

signed main() {
	ios::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);
	int n, ans = 0;
	cin >> n;
	for (int i = 0; i < n; i++) {
		cin >> s[i].first >> s[i].second;
		mx[s[i].first]++;
		my[s[i].second]++;
	}
	for (int i = 0; i < n; i++) {
		ans += (mx[s[i].first] - 1) * (my[s[i].second] - 1);
	}
	cout << ans;
	return 0;
}

• Subtask 1: 100 / 100