public void Insert(T key)
{
BSTTreeNode <T> node = new BSTTreeNode <T>(key);
BSTTreeNode <T> parentNode = null;
BSTTreeNode <T> current = _Root;
while (current != null)
{
parentNode = current;
if (current.Value.CompareTo(key) > 0)
{
current = current.Left;
}
else
{
current = current.Right;
}
}
node.Parent = parentNode;
if (parentNode == null)
{
_Root = node;
return;
}
if (parentNode.Value.CompareTo(key) > 0)
{
parentNode.Left = node;
}
else
{
parentNode.Right = node;
}
}
private BSTTreeNode <T> _Minimum(BSTTreeNode <T> node)
{
BSTTreeNode <T> current = node;
while (current.Left != null)
{
current = current.Left;
}
return(current);
}
private BSTTreeNode <T> _Maximum(BSTTreeNode <T> node)
{
BSTTreeNode <T> current = node;
while (current.Right != null)
{
current = current.Right;
}
return(current);
}
public void Delete(BSTTreeNode <T> node)
{
BSTTreeNode <T> delNode = null;
if (node.Left == null || node.Right == null)
{
delNode = node;
}
else
{
delNode = Successor(node);
}
BSTTreeNode <T> child = null;
if (delNode.Left != null)
{
child = delNode.Left;
}
else
{
child = delNode.Right;
}
if (child != null)
{
child.Parent = delNode.Parent;
}
if (delNode.Parent == null)
{
_Root = child;
}
else
{
if (delNode.Parent.Left == delNode)
{
delNode.Parent.Left = child;
}
else
{
delNode.Parent.Right = child;
}
}
if (node != delNode)
{
node.Value = delNode.Value;
}
}
public BSTTreeNode <T> Search(T key)
{
BSTTreeNode <T> current = _Root;
while (current != null && current.Value.CompareTo(key) != 0)
{
if (current.Value.CompareTo(key) > 0)
{
current = current.Left;
}
else
{
current = current.Right;
}
}
return(current);
}
public BSTTreeNode <T> Predecessor(BSTTreeNode <T> node)
{
if (node == null)
{
throw new ArgumentNullException();
}
if (node.Left != null)
{
return(_Maximum(node.Left));
}
var current = node;
var parent = node.Parent;
while (parent != null && parent.Left == current)
{
current = parent;
parent = parent.Parent;
}
return(parent);
}
