Submission #645588

#	Time	Username	Problem	Language	Result	Execution time	Memory
645588		ymm	Star triangles (IZhO11_triangle)	C++17	100 / 100	307 ms	8144 KiB

triangle

#include <bits/stdc++.h>
#define Loop(x,l,r) for (ll x = (l); x < (r); ++x)
#define LoopR(x,l,r) for (ll x = (r)-1; x >= (l); --x)
typedef long long ll;
typedef std::pair<int, int> pii;
typedef std::pair<ll , ll > pll;
using namespace std;

int main()
{
	cin.tie(0) -> sync_with_stdio(false);
	int n;
	map<int, int> X, Y;
	vector<pii> a;
	cin >> n;
	while (n--) {
		int x, y;
		cin >> x >> y;
		X[x]++;
		Y[y]++;
		a.push_back({x, y});
	}
	ll ans = 0;
	for (auto [x, y] : a)
		ans += (ll)(X[x]-1) * (Y[y]-1);
	cout << ans << '\n';
}

• Subtask 1: 100 / 100