//------------------------------------------------------------------------------
// Add Node below Below. Doesn't update any clusters, weights, etc.
void Tree::AddNodeBelow (NodePtr Node, NodePtr Below)
{
NodePtr Ancestor = NewNode ();
Ancestor->SetChild (Node);
Node->SetAnc (Ancestor);
NodePtr q = Below->GetAnc ();
Internals++;
if (Node->IsLeaf())
Leaves++;
if (q == NULL || Below == q->GetChild())
{
Node->SetSibling (Below);
Ancestor->SetAnc (q);
Ancestor->SetSibling (Below->GetSibling());
Below->SetSibling (NULL);
Below->SetAnc (Ancestor);
if (q == NULL)
Root = Ancestor;
else
q->SetChild (Ancestor);
}
else
{
// Get left sibling of Below
NodePtr r = Below->LeftSiblingOf();
while (Below != r->GetSibling())
r = r->GetSibling();
Node->SetSibling (Below);
Ancestor->SetAnc (q);
Ancestor->SetSibling (Below->GetSibling());
Below->SetSibling (NULL);
Below->SetAnc (Ancestor);
r->SetSibling (Ancestor);
}
}
NodePtr Tree::RemoveNode (NodePtr Node)
{
NodePtr result = NULL;
if (Node == Root)
{
if (Leaves == 1)
{
Root = NULL;
Node->SetAnc (NULL);
Leaves = Internals = 0;
}
return result;
}
NodePtr p;
NodePtr Ancestor = Node->GetAnc();
if (Ancestor->GetDegree() == 2)
{
// ancestor is binary, so remove node and its ancestor
if (Node->IsTheChild ())
p = Node->GetSibling();
else
p = Ancestor->GetChild();
NodePtr q = Ancestor->GetAnc();
p->SetAnc (q);
if (q != NULL)
{
if (Ancestor->IsTheChild())
q->SetChild (p);
else
{
NodePtr r = Ancestor->LeftSiblingOf ();
r->SetSibling (p);
}
p->SetSibling (Ancestor->GetSibling());
result = p;
}
else
{
// Ancestor is the root
Root = p;
p->SetSibling (NULL);
result = p;
}
delete Ancestor;
Internals--;
if (Node->IsLeaf())
Leaves--;
Node->SetAnc (NULL);
Node->SetSibling (NULL);
}
else
{
// polytomy, just remove node
NodePtr q;
if (Node->IsTheChild())
{
Ancestor->SetChild (Node->GetSibling());
q = Node->GetSibling ();
}
else
{
q = Node->LeftSiblingOf ();
q->SetSibling (Node->GetSibling ());
}
Node->SetSibling (NULL);
Node->SetAnc (NULL);
if (Node->IsLeaf())
Leaves--;
Ancestor->SetDegree (Ancestor->GetDegree() - 1);
result = q;
}
}
