P1223

#include <bits/stdc++.h>
using namespace std;
int n,ans;
pair <int,int> num [1000005];
bool cmd(pair <int,int> a,pair <int,int> b)
{
	return a.first < b.first;
}
int main()
{
	cin >> n;
	for (int i = 1;i <= n;i++)
	{
		int x;
		cin >> x;
		num[i] = make_pair(x,i);
	}
	sort(num,num + 1 + n,cmd);
	for (int i = 1;i <= n;i++)
	{
		cout << num[i].second << ' ';
		ans += num[i].first * (n - i);
	}
	cout <<  fixed << setprecision(2);
    cout << endl  << (double)ans / n;
	return 0;
}

不知道这题咋错的，感觉自己挺唐