/* Add a new element to the skip list:
param: slst -- pointer to the skip list
param: e -- element to be added
pre: slst is not null
post: the new element is added to the lowest list and randomly to higher-level lists */
void addSkipList(struct skipList *slst, TYPE e)
{
/* Check if slst is null */
assert(slst);
struct skipLink *downLink, *newLink;
downLink = skipLinkAdd(slideRightSkipList(slst->topSentinel,e),e);
/* FIX ME*/
while(downLink)
{
/* Create new express lane with new head and new link */
newLink = newSkipLink(e, 0, downLink);
struct skipLink* newHead = newSkipLink(0, newLink, slst->topSentinel);
/* Update the new skipList top sentinel to point to new list */
slst->topSentinel = newHead;
/* If need to make new list, update downLink, else set to null */
if(flipSkipLink())
downLink = newLink;
else
downLink = 0;
}
/* Increase size */
slst->size++;
}
/* Add a new element to the skip list:
param: slst -- pointer to the skip list
param: e -- element to be added
pre: slst is not null
post: the new element is added to the lowest list and randomly to higher-level lists */
void addSkipList(struct skipList *slst, TYPE e)
{
struct skipLink *downLink, *newLink;
downLink = skipLinkAdd(slideRightSkipList(slst->topSentinel, e), e);
if (downLink != 0 && flipSkipLink()) {
struct skipLink* newTopSentinel = (struct skipLink *) malloc(sizeof(struct skipLink));
newLink = newSkipLink(e, 0, downLink);
newTopSentinel->next = newLink;
newTopSentinel->down = slst->topSentinel;
slst->topSentinel = newTopSentinel;
}
slst->size++;
}
/* Add a new skip link recursively
param: current -- pointer to a place in the list where the new element should be inserted
param: e -- the value to create a link for
pre: current is not NULL
post: a link to store the value */
struct skipLink* skipLinkAdd(struct skipLink * current, TYPE e) {
struct skipLink *newLink, *downLink;
newLink = 0;
if (current->down == 0) {
newLink = newSkipLink(e, current->next, 0);
current->next = newLink;
}
else {
downLink = skipLinkAdd(slideRightSkipList(current->down, e), e);
if (downLink != 0 && flipSkipLink()) {
newLink = newSkipLink(e, current->next, downLink);
current->next = newLink;
}
}
return newLink;
}
