题解

#include<iostream>
#include<cstdio>
#include<algorithm>
using namespace std;
struct water{
    int id,time;
}a[1010];
bool cmp(water a,water b){
    return a.time<b.time;
}
int main(){
    int n,sum1=0,sum2=0;
    cin>>n;
    for(int i=0;i<n;i++){
        cin>>a[i].time;
        a[i].id=i+1;
    }
    sort(a,a+n,cmp);
    for(int i=0;i<n;i++){
        cout<<a[i].id<<' ';
    }
    for(int i=0;i<n-1;i++){
        sum1+=a[i].time;
        sum2+=sum1;
    }
    printf("\n%.2f",sum2*1.0/n);
    return 0;
}