Submission #1100534

#	Time	Username	Problem	Language	Result	Execution time	Memory
1100534		vjudge1	Star triangles (IZhO11_triangle)	C++17	100 / 100	322 ms	17228 KiB

triangle

//#pragma GCC optimize("O3,unroll-loops")
//#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#define ll long long
#define F first
#define S second
#define ull unsigned long long
#define db double
#define ldb long double
#define pb push_back
#define pf push_front
#define ppb pop_back
#define ppf pop_front
#define yes cout<<"YES\n"
#define no cout<<"NO\n"
#define ordered_set tree<ll,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update>
#define all(x) x.begin(), x.end()

const int mod = 1e9 + 7;
const int N = 500001;

using namespace std;
using namespace __gnu_pbds;

ll n, m, a, b, c, d, e;
map <pair <ll, ll>, ll> cnt;
pair <ll, ll> p[N];

ll gcd (ll a, ll b){while (a > 0 && b > 0){if (a >= b){a %= b;}else{b %= a;}}return a + b;}
ll binpow (ll a, ll b){
	a %= mod;if (b == 0){return 1;}
	else if (b % 2 == 1){
		return binpow (a, b - 1) % mod * a % mod;
	}
	else{
		ll t = binpow (a, b / 2) % mod;
		return t * t % mod;
	}
}

signed main (){
	ios_base::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);
	cin >> n;
	for (int i = 1; i <= n; i++){
		cin >> p[i].first >> p[i].second;
		cnt[{1, p[i].first}]++;
		cnt[{2, p[i].second}]++;
	}
	for (int i = 1; i <= n; i++){
		a += (cnt[{1, p[i].first}] - 1) * (cnt[{2, p[i].second}] - 1);
	}
	cout << a;
}

• Subtask 1: 100 / 100