Submission #212870

#	Time	Username	Problem	Language	Result	Execution time	Memory
212870		islingr	Star triangles (IZhO11_triangle)	C++14	100 / 100	360 ms	12456 KiB

triangle

#include <algorithm>
#include <iostream>
#include <vector>
#include <map>
using namespace std;

#define rep(i, a, b) for (auto i = (a); i < (b); ++i)
#define per(i, a, b) for (auto i = (b) - 1; i >= (a); --i)
#define trav(x, v) for (auto &x : v)
#define ff first
#define ss second

using ll = int64_t;

signed main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	int n; cin >> n;
	vector<pair<int, int>> v(n);
	map<int, int> x, y;
	trav(p, v) {
		cin >> p.ff >> p.ss;
		++x[p.ff]; ++y[p.ss];
	}
	ll ans = 0;
	trav(p, v) ans += 1ll * (x[p.ff] - 1) * (y[p.ss] - 1);
	cout << ans;
}

• Subtask 1: 100 / 100