/**
 * set.c
 *   Implementation of the two key set operations.
 */

#include "set.h"

#define SIZE 31

struct element {
  void *data;
  struct element *next;
}

struct element *stuff[SIZE];


/**
 * Find the first node in elements that contains value.
 * Returns NULL if it's not there.
 */
element *tmp
lookup(element *elements, void *value)
{
  if (elements == NULL)
    return NULL;
  else if (elements->data == value)
    return elements;
  else
    lookup (elements->next, value);
} 

void 
add(void *ptr)
{
  // Apply the hash function
  unsigned location = ((unsigned) ptr) % SIZE;

  // See if there's something there
  element *tmp = lookup(stuff[location]);
  if (tmp == NULL)
    {
      // Add it to the list at that spot in the array 
      tmp = malloc (sizeof (struct element));
      tmp->data = ptr;
      tmp->next = stuff[location];
      stuff[location] = tmp;
    }
}

int 
contains(void *ptr)
{
  // Apply the hash function
  unsigned location = ((unsigned) ptr) % SIZE;
  return (lookup(stuff[location], ptr) != NULL);
}