Submission #913459

#	Time	Username	Problem	Language	Result	Execution time	Memory
913459		daoquanglinh2007	Star triangles (IZhO11_triangle)	C++17	100 / 100	417 ms	15700 KiB

triangle

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

#define int long long

const int NM = 3e5;

int N, x[NM+5], y[NM+5], ans = 0;
map <int, int> f, g;

signed main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	
	cin >> N;
	for (int i = 1; i <= N; i++){
		cin >> x[i] >> y[i];
		f[x[i]]++;
		g[y[i]]++;
	}
	for (int i = 1; i <= N; i++){
		ans += (f[x[i]]-1)*(g[y[i]]-1);
	}
	cout << ans;
	return 0;
}

• Subtask 1: 100 / 100