Submission #493515

#	Time	Username	Problem	Language	Result	Execution time	Memory
493515		reni	Star triangles (IZhO11_triangle)	C++14	100 / 100	131 ms	14172 KiB

triangle

#include<iostream>
#include<unordered_map>
#define endl '\n'
using namespace std;
unordered_map<long long, long long>mpx, mpy;
long long a[300000][2];
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    long long i,j,x,y,n, br=0;

    cin>>n;

    for(i=0;i<n;i++)
    {
        cin>>x>>y;

        a[i][0]=x; a[i][1]=y;

        mpx[x]++;
        mpy[y]++;
    }
    for(i=0;i<n;i++)
    {
        x=a[i][0]; y=a[i][1];
        if(mpx.count(x) && mpy.count(y))br+=(mpx[x]-1)*(mpy[y]-1);
    }

    cout<<br<<endl;



}

Compilation message (stderr)

triangle.cpp: In function 'int main()':
triangle.cpp:13:17: warning: unused variable 'j' [-Wunused-variable]
   13 |     long long i,j,x,y,n, br=0;
      |                 ^

• Subtask 1: 100 / 100