/* Lab 8
   Student Names Go Here
 */
#include <stdio.h>

#define kArraySize  5
#define kSentinel   -1.0

/*
 *  Function Using a Sentinel-Controlled Loop to Store Input Data in an Array.
 *  Gets data to place in list until value of sentinel is encountered in
 *  the input.
 *  Returns number of values stored.
 *  Stops input prematurely if there are more than list_size data values before
 *  the sentinel or if invalid data is encountered.
 *  Pre:  sentinel and list_size are defined and list_size is the declared size of
 *        list
 */
int
fill_to_sentinel(int list_size,    /* input - declared size of list */
       double  sentinel,    /* input - end of data value in input list  */
       double  list[])      /* output - array of data */
{
      double item;
      int    num_items;
      int    status;

      /* Sentinel input loop  */
      num_items = 0;
      status = scanf("%lf", &item);
      while (status == 1  &&  item != sentinel  && num_items < list_size) 
      {
         list[num_items] = item;
         ++num_items;
         status = scanf("%lf", &item);
      }

      /* Issues error message on premature exit */
      if (status != 1) 
      {
         printf("\n*** Error in data format ***\n");
         printf("*** Using first %d data values ***\n", num_items);
      } 
      else if (num_items >= list_size) 
      {
         printf("\n*** Error: number of items exceeds array size ***\n");
         printf("*** Using first %d data values ***\n", num_items);
      }

      /* return used portion of array  */
      return num_items;
}

int
main(void)
{
      double table[kArraySize];
      int    in_use;     /* number of elements of table in use */
      int    index;   /* loop index */

      printf("Enter data items terminated by -1.\n");
      in_use = fill_to_sentinel(kArraySize, kSentinel, table);

      printf("List of data values\n");
      for  (index = 0;  index < in_use;  ++index)
      {
          printf("%13.3f\n", table[index]);
      }   

      return (0);
}