Submission #888259

#	Time	Username	Problem	Language	Result	Execution time	Memory
888259		presko	Star triangles (IZhO11_triangle)	C++14	0 / 100	0 ms	348 KiB

triangle

#include<iostream>
#include<bits/stdc++.h>
#define MAXN 300010
using namespace std;
map<int,int> row,col;
pair<int,int> p[MAXN];
int main()
{
    int n;
    long long ans=0;
    ios_base::sync_with_stdio(false);
    cin>>n;
    for(int i=1;i<=n;i++)
    {
        cin>>p[i].first>>p[i].second;
        row[p[i].second]++;
        col[p[i].first]++;
    }
    for(int i=1;i<=n;i++)
    {
        long long l=row[p[i].first]-1;
        long long r=row[p[i].second]-1;
        l=l*r;
        ans+=l;
    }
    cout<<ans<<"\n";
}

• Subtask 1: 0 / 100