public RBValNode(T val, RBNode <T> leftNode = null, RBNode <T> rightNode = null, RBNode <T> parent = null)
{
base.val = val;
left = leftNode;
if (leftNode == null)
{
left = new RBNullNode <T>();
}
right = rightNode;
if (rightNode == null)
{
right = new RBNullNode <T>();
}
this.parent = parent;
}
public void Delete(RBNode <T> nodeToDelete)
{
//Do a BST delete. If Delete() is called on another node (in a special case) then the check is CANCELED on the original "deleted" node.
if (nodeToDelete.left is RBNullNode <T> && nodeToDelete.right is RBNullNode <T> )
{
//no children
RBNode <T> oldNode = nodeToDelete;
RBNode <T> newNode = new RBNullNode <T>();
DeleteCheck(oldNode, newNode);
if (nodeToDelete == topNode) //roundabout way to say nodeToDelete = newNode. But that doesn't work because of refs
{
topNode = newNode;
topNode.parent = null;
}
else if (nodeToDelete.parent.left == nodeToDelete)
{
nodeToDelete.parent.left = newNode;
}
else if (nodeToDelete.parent.right == nodeToDelete)
{
nodeToDelete.parent.right = newNode;
}
else
{
throw new Exception("Some kind of parenting issue");
}
}
else if (nodeToDelete.right is RBNullNode <T> )
{
//the only child is left
RBNode <T> oldNode = nodeToDelete;
RBNode <T> newNode = nodeToDelete.left;
DeleteCheck(oldNode, newNode);
if (nodeToDelete == topNode)
{ //roundabout way to say nodeToDelete = newNode. But that doesn't work because of refs
topNode = newNode;
}
else if (nodeToDelete.parent.left == nodeToDelete)
{
nodeToDelete.parent.left = newNode;
}
else if (nodeToDelete.parent.right == nodeToDelete)
{
nodeToDelete.parent.right = newNode;
}
else
{
throw new Exception("Some kind of parenting issue");
}
}
else if (nodeToDelete.left is RBNullNode <T> )
{
//only child is right
RBNode <T> oldNode = nodeToDelete;
RBNode <T> newNode = nodeToDelete.right;
DeleteCheck(oldNode, newNode);
if (nodeToDelete == topNode)
{ //roundabout way to say nodeToDelete = newNode. But that doesn't work because of refs
topNode = newNode;
}
else if (nodeToDelete.parent.left == nodeToDelete)
{
nodeToDelete.parent.left = newNode;
}
else if (nodeToDelete.parent.right == nodeToDelete)
{
nodeToDelete.parent.right = newNode;
}
else
{
throw new Exception("Some kind of parenting issue");
}
}
else
{
RBNode <T> replacer = FindRightestChild(nodeToDelete.left);
nodeToDelete.val = replacer.val;
Delete(replacer);
}
}
