本蒟蒻看了好几遍都未找到错误，今日下载数据次数又偏偏用完了qwq

#include<bits/stdc++.h>
using namespace std;
int read(){
    int x=0,f=1;
    char ch=getchar();
    while(!isdigit(ch)){if(ch=='-')f=-1;ch=getchar();}
    while(isdigit(ch)){x=x*10+ch-'0';ch=getchar();}
    return x*f;
}
const int N = 1e6+10;
struct Info{
	int idx,val;
}a[N];
bool cmp(Info &x,Info &y){
	return x.val<y.val;
}
int main(){
	int n = read();
	for(int i=1;i<=n;i++){a[i].val=read();a[i].idx=i;}
	sort(a+1,a+n+1,cmp);
	
	int cnt = 0;
	for(int i=1;i<n;i++){
		printf("%d ",a[i].idx);
		cnt+=(n-i)*a[i].val;
	}
	printf("%d\n",a[n].idx);
	double ans=cnt;
	ans/=n;
	printf("%.2lf\n",ans);
	return 0;
}