private void Concatenate(PairingHeap <T> priorityQueue)
{
if (null == priorityQueue || null == priorityQueue.head)
{
return;
}
if (null == head)
{
head = priorityQueue.head;
priorityQueue = null;
return;
}
if (head != priorityQueue.head)
{
if (!compareFunctor(head.Value, priorityQueue.head.Value))
{
AddChildNode(priorityQueue.head);
}
else
{
priorityQueue.AddChildNode(head);
head = priorityQueue.head;
}
}
priorityQueue = null;
}
public (bool HasValue, T value) ExtractMinimum()
{
if (null == head)
{
return(false, default(T));
}
var prevHead = head;
T returnValue = head.Value;
if (null == head.child)
{
head = null;
return(true, returnValue);
}
head = head.child;
prevHead.last = true;
prevHead.child = null;
prevHead.left = null;
prevHead.right = null;
head.last = true;
Node <T> nodeToMerge = head.right;
head.right = null;
head.left = null;
while (null != nodeToMerge)
{
var mergedNode = nodeToMerge;
nodeToMerge = nodeToMerge.right;
mergedNode.right = null;
mergedNode.left = null;
mergedNode.last = true;
PairingHeap <T> queueToMerge = new PairingHeap <T>(mergedNode, compareFunctor);
Concatenate(queueToMerge);
}
return(true, returnValue);
}