ZOJ 1543 水题 求培养皿的最小重量

#include<stdio.h>
#include<stdlib.h>
#include<math.h>

int cmp(const void *a,const void *b)//这里要用double貌似用int不行
{
    return *(double *)a > *(double *)b ? 1 : -1;
}

int main()
{
    int i, n, ncases;
    double total;  
    double weight[101];

    while( scanf("%d",&ncases) != EOF)
    {
       for(i=0; i<ncases; i++)
       {
           scanf("%lf", &weight[i]);    
       }   
       qsort(weight,ncases,sizeof(weight[0]),cmp);  
       total = weight[ncases-1];
       for(i=ncases-2; i>=0; i--)
       {  
         total = 2*sqrt(total*weight[i]);  
       }   
       printf("%.3lf\n",total);    
    }      
    return 0;       
}