L-23 MCS 275 Fri 2 Mar 2001

/* L-23 MCS 275 Fri 2 Mar 2001 managing items in store */

#include <stdio.h>
#include <stlib.h>

#define max 80     /* maximal number of characters in string */

struct item
{
   int  label;
   char *name;
   float price;
};

struct item *create_inventory ( int n );
/* returns an inventory of n items, read from standard input */
struct item *ptr_create_inventory ( int n );
/* pointer version of creation of inventory */
void display_inventory ( int n, struct item invent[] );
/* displays the inventory of n items */
void ptr_display_inventory ( int n, struct item invent[] );
/* pointer version of display_inventory */

int main()
{
   struct item *invent;
   int n;

   printf("Give the number of items : ");
   scanf("%d",&n);

   invent = ptr_create_inventory(n);
   printf("displaying with the array version...\n");
   display_inventory(n,invent);
   printf("displaying with the pointer version...\n");
   ptr_display_inventory(n,invent);

   return 0;
}

struct item *create_inventory ( int n )
{
   int i;
   struct item *invent = malloc(n*sizeof(struct item));

   for (i = 0; i < n; i++)
   {
      printf("Reading data for item %d :\n", i+1);
      printf("  Give label : "); scanf("%d", &invent[i].label);
      invent[i].name = calloc(max,sizeof(char));
      printf("  Give name  : "); scanf("%s", invent[i].name);
      printf("  Give price : "); scanf("%f", &invent[i].price);
   }

   return invent;

}

struct item *ptr_create_inventory ( int n )
{
   struct item *invent = malloc(n*sizeof(struct item));
   struct item *p;
   int i = 1;

   for (p = invent; p < invent+n; p++)
   {
      printf("Reading data for item %d :\n", i++);
      printf("  Give label : "); scanf("%d", &p->label);
      p->name = calloc(max,sizeof(char));
      printf("  Give name  : "); scanf("%s", p->name);
      printf("  Give price : "); scanf("%f", &p->price);
   }

   return invent;

}

void display_inventory ( int n, struct item invent[] )
{
   int i;

   printf("The inventory of %d items :\n", n);
   for (i = 0; i < n; i++)
      printf("  %d %10s %7.2f\n",
             invent[i].label, invent[i].name, invent[i].price);
}

void ptr_display_inventory ( int n, struct item *invent )
{
   struct item *p;

   printf("The inventory of %d items :\n", n);
   for (p = invent; p < invent+n; p++)
      printf("  %d %10s %7.2f\n", p->label, p->name, p->price);
}