3WA，求调。

#include<bits/stdc++.h>
using namespace std;
struct water{
 int id;
 long long time;
}t[1001];
int n,ge=0,tot=0;
double ans=0.0;
bool cmp(water w1,water w2)
{if(w1.time==w2.time) return w1.id>w2.id;
 return w1.time<w2.time;
}
int main()
{cin>>n;
 for(int i=1;i<=n;i++)
 {cin>>t[i].time;
  t[i].id=i;
 }
 sort(t+1,t+n+1,cmp);
 for(int i=1;i<=n;i++) cout<<t[i].id<<" ";
 cout<<endl;
 for(int i=1;i<n;i++)
 {ge+=t[i].time;
  tot+=ge;
 }
 ans=(double)tot/n;
 printf("%.2lf",ans);
 return 0;
}