COMP1721 - Higher Computing 1B

1. Recursive:

   /*
    * return true iff value occurs in list
    */
   int
   member(int value, linked_list list) {
   	return list != NULL && (list->data == value || member(value, list->next));
   }
   

   Iterative:

   /*
    * return true iff value occurs in list
    */
   int
   member(int value, linked_list list) {
   	list_node *n;
   	for (n = list; n != NULL; n = n->next)
   		if (n->data == value)
   			return 1;
   	return 0;
   }
   
   /*
    * convert string to a linked list
    */
   linked_list
   string_to_list(char *s) {
       char *t;
       linked_list list = NULL;
       while (*s != '\0') {
           int i = strtol(s, &t, 10);
           if (s != t) {
               /*
                * parsed an int from string
                * add to list
                */
               list = append(i, list);
               s = t;
               continue;
           }
           s++;
       }
       return list;
   }
   
   
   /*
    * convert list to malloc'ed string
    */
   char *
   list_to_string(linked_list list) {
       char      buffer[32]; /* must be big enough to hold the largest int */
       list_node *n;
       char      *s, *t;
       int       n_chars;
       
       n_chars = 3;  /* [] and '\0' */
       for (n = list; n != NULL; n = n->next) {
           sprintf(buffer, "%d", n->data);
           n_chars += strlen(buffer);
           if (n->next != NULL)
               n_chars += 2;  /* ", " */
       }
       s = malloc(n_chars);
       if (s == NULL) {
           fprintf(stderr, "out of memory\n");
           exit(1);
       }
       t = s;
       *t = '[';
       t++;
       for (n = list; n != NULL; n = n->next) {
           sprintf(t, "%d", n->data);
           t += strlen(t);
           
           if (n->next != NULL) {
               strcat(t, ", ");
               t += 2;  /* ", " */
           }
       }
       *t = ']';
       t++;
       *t = '\0';
       return s;
   }