Submission #1220985

#	Time	Username	Problem	Language	Result	Execution time	Memory
1220985		boclobanchat	Star triangles (IZhO11_triangle)	C++20	100 / 100	381 ms	22752 KiB

triangle

#include<bits/stdc++.h>
using namespace std;
map<int,int> mpa,mpb;
map< pair<int,int>,int > mp;
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int n;
    cin>>n;
    for(int i=1;i<=n;i++)
    {
    	int x,y;
    	cin>>x>>y;
    	mpa[x]++,mpb[y]++,mp[{x,y}]++;
	}
	long long ans=0;
	for(auto v:mp) ans+=1LL*v.second*(mpa[v.first.first]-v.second)*(mpb[v.first.second]-v.second);
	cout<<ans;
}

• Subtask 1: 100 / 100