//
// Run as:  (ulimit -v 50000;  a.out > err)
//

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

struct List
{
int          value;
struct List *next;
};

void print(struct List *h);  	// Declaration
struct List *insert (struct List *h, struct List *e);

/* ====================================================
   delete(h): delete the first elem from the list h
              return new list
   ==================================================== */
struct List *delete (struct List *h)
{
   struct List *newHead;

   if ( h != NULL)
   {
      return h->next;  // Not so fast in C... !
   }
   else
      return NULL;
}

int main(int argc, char *argv[])
{
   struct List *head = NULL;
   int c = 0;

   while(1)
   {
      printf("%d\n", ++c);  // Keep a count

      // Insert
      for (int i = 1; i <= 10; i++)
      {
          struct List *e = malloc( sizeof(struct List) ) ;
          e->value = i;
          head = insert(head, e);       // Insert i at head
          print(head);
      }

      // Delete
      for (int i = 1; i <= 10; i++)
      {
          head = delete(head);          // Delete at head
          print(head);
      }
   }
}

// Insert at head
struct List *insert (struct List *h, struct List *e)
{
    e->next = h;
    return e;     // Return new list that starts at e
}


// Print the list
void print(struct List *h)
{
   while (h != NULL)
   {
      printf("%d ", h->value);
      h = h->next;
   }
   printf("\n");
}