Who can help me?
Why I got WA#6
This is my code
# include <iostream>
using namespace std;
int main ()
{
    int n,i,j,k;
    int x[10002],y[10002],h[10002];
    cin>>n;
    for(i=1;i<=n;i++)
    {
        cin>>x[i]>>y[i];
        h[i]=i;
    }
    for(i=1;i<n;i++)
        for(j=i+1;j<=n;j++)
        {
            if((x[j]<x[i]) || (x[j]==x[i] && y[j]>y[i]))
            {
                k=x[i];x[i]=x[j];x[j]=k;
                k=y[i];y[i]=y[j];y[j]=k;
                k=h[i];h[i]=h[j];h[j]=k;
            }
        }
    for(i=1;i<=(n/2)+1;i+=2)
        cout<<h[i]<<" "<<h[i+1]<<endl;
    return 0;
}

problem in output
if you use
    for(...;i+=2)
you have to use
    for(...;i<=n;...)

//like this
for(i=1;i<=n;i+=2)
cout<<h[i]<<" "<<h[i+1]<<endl;