FibonacciHeapNode<Key, Data> * FibonacciHeap<Key, Data>::Delete(FibonacciHeapNode<Key, Data> * node)
{
FibonacciHeapNode<Key, Data> * parent = node->m_pParent;
if (parent != NULL) {
Cut(node, parent);
CascadingCut(parent);
}
m_pMin = node;
return ExtractMin();
}
void fibonacci_heap::CascadingCut(Node* y) {
Node* z = y->parent;
if (z != nullptr) {
if (y->marked == false) {
y->marked = true;
} else {
Cut(y,z);
CascadingCut(z);
}
}
}
static void * ReplaceKeyData(PQueue *h, PQueueElement *x, intptr_t key, void *data)
{
void *odata;
int okey;
PQueueElement *y;
int r;
odata = x->Data;
okey = x->Key;
/*
* we can increase a key by deleting and reinserting, that
* requires O(lgn) time.
*/
if ((r = comparedata(h, key, data, x)) > 0) {
/* XXX - bad code! */
abort();
DeleteElement(h, x);
if (data) memcpy(x->Data , data,h->ElementSize);
x->Key = key;
insertel(h, x);
return odata;
}
if (data) memcpy(x->Data , data, h->ElementSize);
x->Key = key;
/* because they are equal, we don't have to do anything */
if (r == 0)
return odata;
y = x->Parent;
if (okey == key)
return odata;
if (y != NULL && compare(h, x, y) <= 0) {
Cut(h, x, y);
CascadingCut(h, y);
}
/*
* the = is so that the call from delete will delete the proper
* element.
*/
if (compare(h, x, h->Minimum) <= 0)
h->Minimum = x;
return odata;
}
void FibonacciHeap<Key, Data>::CascadingCut(FibonacciHeapNode<Key, Data> * node)
{
FibonacciHeapNode<Key, Data> * parent = node->m_pParent;
if (parent != NULL) {
if (!node->m_bMarked)
node->m_bMarked = true;
else {
Cut(node, parent);
CascadingCut(parent);
}
}
}
FibonacciHeapNode<Key, Data> * FibonacciHeap<Key, Data>::DecreaseKey(FibonacciHeapNode<Key, Data> * node, const Key & newKey)
{
if (newKey < node->m_Key) {
node->m_Key = newKey;
FibonacciHeapNode<Key, Data> * parent = node->m_pParent;
if (parent != NULL && node->m_Key < parent->m_Key) {
Cut(node, parent);
CascadingCut(parent);
}
if (node->m_Key < m_pMin->m_Key) m_pMin = node;
}
return node;
}
void DecreaseKey(heap **H,heap *x,int k)
{
heap *y,*back;
y=x->parent;
x->time=k;
if(y!=NULL && k<y->time)
{
cut(*H,x,y);
CascadingCut(*H,y);
}
if(k<(*H)->time)
(*H)=x;
}
void CascadingCut(heap *H,heap *y)
{
heap *z;
z=y->parent;
if(z!=NULL)
{
if(y->mark==0)
y->mark=1;
else
{
cut(H,y,z);
CascadingCut(H,z);
}
}
}
void fibonacci_heap::DecreaseKey(Node* x, ii key) {
if (key > x->key)
return; // error: new key is greater than current key
x->key = key;
Node* y = x->parent;
if (y != nullptr && x->key < y->key) {
Cut(x,y);
CascadingCut(y);
}
if (x->key < min->key)
min = x;
}
