Submission #1129678

#	Time	Username	Problem	Language	Result	Execution time	Memory
1129678		zhasyn	Star triangles (IZhO11_triangle)	C++20	100 / 100	381 ms	8188 KiB

triangle

#include <bits/stdc++.h>
#define pb push_back
#define pf push_front
using namespace std;
#define F first
#define S second
typedef long long ll;
#define pii pair <int, int>
#define pll pair <ll, ll>
typedef long double ld;
const ll N = 3 * 1e5 + 100, M = 500 + 10, len = 315, inf = 1e18;
const ll mod = 998244353;
ll um(ll a, ll b){
	return (1LL * a * b) % mod;
}
ll subr(ll a, ll b){
	return ((1LL * a - b) % mod + mod) % mod;
}
ll bp(ll x, ll step){
	ll res = 1;
	while(step){
		if(step & 1) res = um(res, x);
		x = um(x, x);
		step /= 2;
	}
	return res;
}
ll inv(ll x){
	return bp(x, mod - 2);
}
ll a[N], b[N];
int main() {
	//ios_base::sync_with_stdio(false);
	//cin.tie(nullptr);
	//cout.tie(nullptr);
	ll n;
	cin >> n;
	map<int, int> mp, mp1;
	for(ll i = 0; i < n; i++){
		cin >> a[i] >> b[i];
		mp[a[i]]++;
		mp1[b[i]]++;
	}
	ll ans = 0;
	for(ll i = 0; i < n; i++){
		ans += (mp[a[i]] - 1) * (mp1[b[i]] - 1);
	}
	cout << ans;
  return 0;
}

• Subtask 1: 100 / 100