Submission #40887

#	Time	Username	Problem	Language	Result	Execution time	Memory
40887		Abelyan	Star triangles (IZhO11_triangle)	C++14	100 / 100	419 ms	38988 KiB

triangle

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

const int N=300000;
map<int,int> x,y;
int a[N],b[N];

int main() {
	ios_base::sync_with_stdio(false);
	long long ans=0;
	int n;
	cin>>n;
	for (int i=0;i<n;i++){
		cin>>a[i]>>b[i];
		x[a[i]]++;
		y[b[i]]++;
	}
	for (int i=0;i<n;i++){
		ans+=(long long)(x[a[i]]-1)*(long long)(y[b[i]]-1);
	}
	cout<<ans<<endl;
	return 0;
}

• Subtask 1: 100 / 100