//STL教你做人系列#include<stdio.h>#include<iostream>#include<math.h>#include<algorithm>using namespace std;int n,a[3100];int main(){    cin>>n;    for(int i=0;i<n;i++)        cin>>a[i];    cout<<n<<endl;    for(int i=0;i<n;i++)    {        int k=min_element(a+i,a+n)-a;//找到[a+i,a+n)里面的最小元素的下标        //cout<<k<<endl;        swap(a[i],a[k]);        cout<<i<<" "<<k<<endl;    }    return 0;}