Submission #976478

#	Time	Username	Problem	Language	Result	Execution time	Memory
976478		vjudge1	Star triangles (IZhO11_triangle)	C++17	100 / 100	281 ms	13208 KiB

triangle

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

#define ll long long
#define pb push_back
#define pll pair<ll,ll>

const ll MOD=1e9+7;

//#define ll int
//KALAU TAKUT RTE

bool cmp (pair<ll,ll> x, pair<ll,ll>y){
	return x.second < y.second;
}

signed main(){
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	ll n; cin>>n;
	ll x[n+1], y[n+1];
	map<ll,ll> cntx, cnty;
	for (int i=1; i<=n;i++){
		cin>>x[i]>>y[i];
		cntx[x[i]]++; cnty[y[i]]++;
	}
	
	ll ans=0;
	for (int i=1; i<=n;i++){
		ans+= (cntx[x[i]]-1) * (cnty[y[i]]-1);
	}
	cout<<ans<<endl;
}

• Subtask 1: 100 / 100