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

#define   N   11                     /* size of the array */

enum when {before, after};

typedef   enum when   when;

int    cmp(const void *vp, const void *vq);
                                    /* comparison fct */
void   fill_array(double *a, int n);
void   prn_array(when val, double *a, int n);

int main(void)
{
   double   a[N];

   fill_array(a, N);
   prn_array(before, a, N);
   qsort(a, N, sizeof(double), cmp);
   prn_array(after, a, N);
   return 0;
}

int cmp(const void *vp, const void *vq)
{
   const double   *p = vp;
   const double   *q = vq;
   double          diff = *p - *q;

   return ((diff >= 0.0) ? ((diff > 0.0) ? -1 : 0) : +1); } 

void fill_array(double *a, int n)
{
   int   i;

   srand(time(NULL));                  /* seed rand() */
   for (i = 0; i < n; ++i)
      a[i] = (rand() % 1001) / 10.0;
}

void prn_array(when val, double *a, int n)
{
   int   i;

   printf("%s\n%s%s\n",
       "---", 
      ((val == before) ? "Before " : "After "), "sorting:");
   for (i = 0; i < n; ++i) {
      if (i % 6 == 0)  putchar('\n');
      printf("%10.1f", a[i]);
   }
   putchar('\n'); 
}