算法设计与分析-最优服务次序问题

#include<iostream>
#include<algorithm>
#include<vector>

using namespace std;

bool run()
{
    int n;
    if(!(cin>>n))  return false;
    vector<int> f(n);
    for(int i=0; i<n; i++)
    {
        cin>>f[i];
    }
    sort(f.begin(),f.end());
    double sum=0,wait=0;
    for(int i=0; i<n; i++)
    {
        wait=wait+f[i];
        sum=sum+wait;
    }
    printf("%.2lf\n",sum/n);
    return true;
}

int main()
{
    //freopen("f:\\7016.txt","rt",stdin);