Submission #975621

#	Time	Username	Problem	Language	Result	Execution time	Memory
975621		vjudge1	Star triangles (IZhO11_triangle)	C++17	100 / 100	426 ms	8088 KiB

triangle

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

using ll = long long;

signed main() {
	int n;
	cin >> n;

	map<int, vector<int>> xx;
	map<int, ll> yy;

	for (int i = 0; i< n; i++) {
		int x, y;
		cin >> x >> y;
		xx[x].push_back(y);
		yy[y]++;
	}

	ll ans = 0;

	for (auto [x, v] : xx) {
		for (int y : v) {
			ans += (yy[y] - 1LL) * (ll) (v.size() - 1LL);		
		}
	}

	cout << ans << '\n';
}

• Subtask 1: 100 / 100