/*--------------------------------------------------------------------*/
/* sort5.c                                                            */
/* Author: Bob Dondero                                                */
/* The standard qsort() function                                      */
/*--------------------------------------------------------------------*/

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

enum {INITIAL_ARRAY_LENGTH = 2};
enum {ARRAY_GROWTH_FACTOR = 2};

/*--------------------------------------------------------------------*/

static int compareDouble(const void *pvItem1, const void *pvItem2)

/* Return -1, 0, or 1 depending upon whether *pvItem1 is
   less than, equal to, or greater than *pvItem2, respectively. */

{
   double *pdItem1 = (double*)pvItem1;
   double *pdItem2 = (double*)pvItem2;

   if (*pdItem1 < *pdItem2) return -1;
   if (*pdItem1 > *pdItem2) return 1;
   return 0;
}

/*--------------------------------------------------------------------*/

int main(int argc, char *argv[])

/* Read numbers from stdin, and write them in ascending order to
   stdout.  Return 0. */

{
   double *pdArray;
   int iCount;
   int iLength;
   double dNumber;
   int i;

   /* Dynamically allocate an array. */

   iLength = INITIAL_ARRAY_LENGTH;
   pdArray = (double*)calloc((size_t)iLength, sizeof(double));
   assert(pdArray != NULL);

   /* Read the numbers into the array. */

   iCount = 0;
   while (scanf("%lf", &dNumber) != EOF)
   {
      if (iCount == iLength)
      {
         iLength *= ARRAY_GROWTH_FACTOR;
         pdArray =
            (double*)realloc(pdArray, iLength * sizeof(double));
         assert(pdArray != NULL);
      }
      pdArray[iCount] = dNumber;
      iCount++;
   }

   /* Sort the array. */

   qsort(pdArray, (size_t)iCount, sizeof(double), compareDouble);

   /* Write the numbers from the array. */

   for (i = 0; i < iCount; i++)
      printf("%g\n", pdArray[i]);

   /* Free the array. */

   free(pdArray);

   return 0;
}