Submission #1113741

#	Time	Username	Problem	Language	Result	Execution time	Memory
1113741		Agageldi	Star triangles (IZhO11_triangle)	C++17	100 / 100	272 ms	12104 KiB

triangle

/*
ID: agageld1
LANG: C++17
TASK:
*/
#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define N 400005
#define ff first
#define ss second
#define pb push_back
#define sz(s) (int)s.size()

//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

ll n, t;
pair <int,int> a[N];
map <int,int> vis,m;

int main () {
	ios::sync_with_stdio(0);cin.tie(0);
	cin >> n;
	for(int i=1;i<=n;i++) {
		cin >> a[i].ff >> a[i].ss;
		vis[a[i].ff]++;
		m[a[i].ss]++;
	}
	int ans = 0;
	for(int i =1;i<=n;i++) {
		ans += (vis[a[i].ff] - 1) * (m[a[i].ss] - 1);
	}
	cout << ans << '\n';
}

• Subtask 1: 100 / 100