#include<bits/stdc++.h>
using namespace std;
struct T{
	long long a;
	int b;
};
T arr[1000000];
double ans;int brr[100000];
int cmp(T x,T y){
	return x.a<y.a;
}
int main(){
	int n;
	cin>>n;
	cout<<10;
	for(int i = 0;i<n;i++){
	cin>>arr[i].a;
	arr[i].b=i;
	}
	sort(arr,arr+n-1,cmp);
	for(int i =0;i<n;i++){
		cout<<arr[i].b+1<<" ";
		ans+=arr[i].a;
		brr[i]=ans;
	}
	ans=0;
	int i=0;double time=0;
	for(int j=n;j>1;j--) 
 	 {
   		i=n-j;
   		time+=arr[i].a*j;                 
  	}
	printf("%.2lf",time/n);
	return 0;
}

为啥最后两个反了