题解

#include<bits/stdc++.h>
using namespace std;
int n,Max,num;
struct Person{
    int time;
    int id;
}a[1001];
bool cmp(Person a,Person b){
    if(a.time==b.time)return a.id<b.id;
    return a.time<b.time;
}
int main(){
    cin>>n;
    for(int i=1;i<=n;i++){
        cin>>a[i].time;
        a[i].id=i;
    }
    sort(a+1,a+n+1,cmp);
    for(int i=1;i<=n;i++)cout<<a[i].id<<" ";
    cout<<endl;
    for(int i=1;i<=n;i++)num+=(n-i)*a[i].time;
    printf("%.2lf",num*1.0/n);
    return 0;
}