Submission #331862

#	Time	Username	Problem	Language	Result	Execution time	Memory
331862		nandonathaniel	Star triangles (IZhO11_triangle)	C++14	100 / 100	465 ms	12372 KiB

triangle

#include<bits/stdc++.h>
using namespace std;
const int MAXN=300005;

int x[MAXN],y[MAXN];
map<int,int> mpx,mpy;

int main(){
	ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	int n;
	cin >> n;
	for(int i=1;i<=n;i++){
		cin >> x[i] >> y[i];
		mpx[x[i]]++;
		mpy[y[i]]++;
	}
	long long ans=0;
	for(int i=1;i<=n;i++){
		ans=ans+1LL*(mpx[x[i]]-1)*(mpy[y[i]]-1);
	}
	cout << ans << '\n';
	return 0;
}

• Subtask 1: 100 / 100