R4H

#include<iostream>
#include<algorithm>

using namespace std;

long n, a[100001];

void qsort(long l,long r){
    long h,i,j;
    if (l<r){
        h=a[(l+r)/2];
        i=l;j=r;
        while (i<=j){
            while (a[i]<h) i++;
            while (a[j]>h) j--;
            if (i<=j){
                if (i<j){
                    swap(a[i],a[j]);cout<<i<<" "<<j<<endl;
                }
                i++;
                j--;
            }
        }
        qsort(l,j);
        qsort(i,r);
    }
}

int main(){
    cin>>n;
    for(int i=1;i<=n;i++){
        cin>>a[i];
    }
    qsort(1,n);
}