delete_list(list **l, item_type x)
{
list *p; /* item pointer */
list *pred; /* predecessor pointer */
list *search_list(), *predecessor_list();
p = search_list(*l,x);
if (p != NULL) {
pred = predecessor_list(*l,x);
if (pred == NULL) /* splice out out list */
*l = p->next;
else
pred->next = p->next;
free(p); /* free memory used by node */
}
}
llist_t *predecessor_list(llist_t *l, int x)
{
if(l == NULL || l->next == NULL)
return NULL;
if(l->next->item == x)
return l;
else
return predecessor_list(l->next, x);
}
list *predecessor_list(list *l, item_type x)
{
if ((l == NULL) || (l->next == NULL)) {
printf("Error: predecessor sought on null list.\n");
return(NULL);
}
if ((l->next)->item == x)
return(l);
else
return( predecessor_list(l->next, x) );
}
void delete_list(llist_t **l, int x)
{
llist_t *p, *t;
if(NULL == *l)
return;
if(x == (*l)->item) {
t = *l;
*l = (*l)->next;
free(t);
} else {
p = predecessor_list(*l, x);
if(p != NULL) {
t = p->next;
p->next = p->next->next;
free(t);
}
}
}
