问题标题: 酷町堂：1251 0分

1251咋写？最后的等待时间不太会啊

代码:

#include<iostream>
#include<cstdio>
#include<algorithm>
using namespace std;
struct node{
    int time,pos;
}a[10005];
bool cmp(node a,node b){
    if(a.time!=b.time){
        return a.time<b.time;
    }
    return a.pos<b.pos;
}
int main(){
    long long n;
    double sum=0.00;
    cin>>n;
    for(int i=1;i<=n;i++){
        cin>>a[i].time;
        a[i].pos=i;
    }
    sort(a+1,a+1+n,cmp);
    for(int i=1;i<=n;i++){
        int cnt=0;
        cout<<a[i].pos<<' ';
        for(int j=i+1;j<=n;j++){
            cnt++;
        }
        sum+=a[i].time*cnt;
    }
    printf("\n%.2f\n",sum/n);
    return 0;
}