public void removechild(HeapNode node)
{
if (node.parent != this)
{
throw new Exception("Cannot remove child from node that is not it's parent");
}
if (node.issingle())
{
if (child != node)
{
throw new Exception("Cannot remove node that is not a child");
}
child = null;
}
else
{
if (child == node)
{
child = node.next;
}
node.remove();
}
node.parent = null;
node.mark = false;
degree--;
}
public void removeminimum()
{
if (minnode == null)
{
throw new Exception("Cannot remove from empty heap");
}
count--;
if (minnode.child != null)
{
HeapNode c = minnode.child;
while (true)
{
c.parent = null;
c = c.next;
if (c == minnode.child)
{
break;
}
}
minnode.child = null;
minnode.insert(c);
}
if (minnode.next == minnode)
{
if (count != 0)
{
throw new Exception("Heap error: Expected 0 keys. Count is " + count);
}
minnode = null;
return;
}
int logsize = 100;
HeapNode[] degreeroots = new HeapNode[logsize];
maxdegree = 0;
HeapNode currentpointer = minnode.next;
while (true)
{
int currentdegree = currentpointer.degree;
HeapNode current = currentpointer;
currentpointer = currentpointer.next;
while (degreeroots[currentdegree] != null)
{
HeapNode other = degreeroots[currentdegree];
if (current.key > other.key)
{
HeapNode temp = other;
other = current;
current = temp;
}
other.remove();
current.addchild(other);
degreeroots[currentdegree] = null;
currentdegree++;
}
degreeroots[currentdegree] = current;
if (currentpointer == minnode)
{
break;
}
}
minnode = null;
int newmaxdegree = 0;
for (int i = 0; i < logsize; i++)
{
if (degreeroots[i] != null)
{
degreeroots[i].next = degreeroots[i].previous = degreeroots[i];
this._insertnode(degreeroots[i]);
if (i > newmaxdegree)
{
newmaxdegree = i;
}
}
}
maxdegree = newmaxdegree;
}
