RT。 代码如下

#include<bits/stdc++.h>
using namespace std;
struct water
{
	int num,time;
}p[1010];
bool cmp(water a,water b)
{
	if(a.time!=b.time) 
	    return a.time<b.time;
	return a.num<b.num;
}
int n,sum=0;
int main()
{
    cin>>n;
    for(int i=1;i<=n;i++)
    {
    	cin>>p[i].time;
    	p[i].num=i;
    }
    sort(p+1,p+n+1,cmp);
    for(int i=1;i<=n;i++)
    {
    	cout<<p[i].num<<" ";
    	sum+=i*p[n-i].time;
    }
    printf("\n%.2lf\n",1.0*sum/n);
    return 0;
} 

这是82分代码

#include<bits/stdc++.h>
using namespace std;
struct water
{
	int num,time;
}p[1010];
bool cmp(water a,water b)
{
	if(a.time!=b.time) 
	    return a.time<b.time;
	return a.num<b.num;
}
int n,sum=0;
int main()
{
	//freopen("jieshui.in","r",stdin);
	//freopen("jieshui.out","w",stdout);
    scanf("%d", &n); 
    for(int i=1;i<=n;i++)
    {
    	scanf("%d",&p[i].time);
    	p[i].num=i;
    }
    sort(p+1,p+n+1,cmp);
    for(int i=1;i<=n;i++)
    {
    	printf("%d ",p[i].num);
    	sum+=i*p[n-i].time;
    }
    printf("\n%.2lf\n",1.0*sum/n);
    return 0;
} 

这是wa的就很神奇