/* Rebalances the subtree in BT rooted at SUBTREE, which contains
exactly COUNT nodes. */
static void rebalance_subtree (TreeMap *bt, struct Node *subtree, size_t count)
{
struct Node *up = subtree->up;
struct Node **q = down_link (bt, subtree);
tree_to_vine (q);
vine_to_tree (q, count);
(*q)->up = up;
}
/* Deletes P from BT. */
void
bt_delete (struct bt *bt, struct bt_node *p)
{
struct bt_node **q = down_link (bt, p);
struct bt_node *r = p->down[1];
if (r == NULL)
{
*q = p->down[0];
if (*q)
(*q)->up = p->up;
}
else if (r->down[0] == NULL)
{
r->down[0] = p->down[0];
*q = r;
r->up = p->up;
if (r->down[0] != NULL)
r->down[0]->up = r;
}
else
{
struct bt_node *s = r->down[0];
while (s->down[0] != NULL)
s = s->down[0];
r = s->up;
r->down[0] = s->down[1];
s->down[0] = p->down[0];
s->down[1] = p->down[1];
*q = s;
if (s->down[0] != NULL)
s->down[0]->up = s;
s->down[1]->up = s;
s->up = p->up;
if (r->down[0] != NULL)
r->down[0]->up = r;
}
bt->size--;
/* We approximate .707 as .75 here. This is conservative: it
will cause us to do a little more rebalancing than strictly
necessary to maintain the scapegoat tree's height
invariant. */
if (bt->size < bt->max_size * 3 / 4 && bt->size > 0)
{
rebalance_subtree (bt, bt->root, bt->size);
bt->max_size = bt->size;
}
}
/* Deletes P from BT. */
static void Delete(TreeMap *bt, struct Node *p)
{
struct Node **q = down_link (bt, p);
struct Node *r = p->down[1];
if (r == NULL) {
*q = p->down[0];
if (*q)
(*q)->up = p->up;
}
else if (r->down[0] == NULL) {
r->down[0] = p->down[0];
*q = r;
r->up = p->up;
if (r->down[0] != NULL)
r->down[0]->up = r;
}
else {
struct Node *s = r->down[0];
while (s->down[0] != NULL)
s = s->down[0];
r = s->up;
r->down[0] = s->down[1];
s->down[0] = p->down[0];
s->down[1] = p->down[1];
*q = s;
if (s->down[0] != NULL)
s->down[0]->up = s;
s->down[1]->up = s;
s->up = p->up;
if (r->down[0] != NULL)
r->down[0]->up = r;
}
bt->count--;
/* We approximate .707 as .75 here. This is conservative: it
will cause us to do a little more rebalancing than strictly
necessary to maintain the scapegoat tree's height
invariant. */
if (bt->count < bt->max_size * 3 / 4 && bt->count > 0)
{
rebalance_subtree (bt, bt->root, bt->count);
bt->max_size = bt->count;
}
if (bt->DestructorFn)
bt->DestructorFn(p);
iHeap.AddToFreeList(bt->Heap,p);
bt->timestamp++;
}
t_case *my_graph(t_case *cas, int length)
{
t_case *elem;
elem = cas->next;
while (elem != cas)
{
if (!elem->pass)
{
if (up_link(elem, cas, length))
return (NULL);
if (left_link(elem, cas))
return (NULL);
if (right_link(elem, cas, length))
return (NULL);
if (down_link(elem, cas, length))
return (NULL);
}
elem = elem->next;
}
return (cas);
}
