public void Insert(T value)
{
var previous = RbtNode <T> .Nil;
var current = Head;
while (current != RbtNode <T> .Nil)
{
previous = current;
current = current.Value.CompareTo(value) > 0 ? current.Left : current.Right;
}
var newNode = new RbtNode <T>(value, previous, false);
if (previous == RbtNode <T> .Nil)
{
Head = newNode;
}
else if (previous.Value.CompareTo(value) > 0)
{
previous.Left = newNode;
}
else
{
previous.Right = newNode;
}
InsertFixup(newNode);
}
public void Remove(T item)
{
var node = FindNode(item);
if (node == RbtNode <T> .Nil)
{
return;
}
var tmp = node.Left == RbtNode <T> .Nil || node.Right == RbtNode <T> .Nil ? node : GetNextNode(node);
var tmp2 = tmp.Left != RbtNode <T> .Nil ? tmp.Left : tmp.Right;
tmp2.Parent = tmp.Parent;
if (tmp.Parent == RbtNode <T> .Nil)
{
Head = tmp2;
}
else if (tmp == tmp.Parent.Left)
{
tmp.Parent.Left = tmp2;
}
else
{
tmp.Parent.Right = tmp2;
}
if (tmp != node)
{
node.Value = tmp.Value;
}
if (tmp.IsBlack)
{
RemoveFixUp(tmp);
}
}
public RbtNode(T value, RbtNode <T> parent, bool isBlack)
{
Value = value;
Parent = parent ?? Nil;
Left = Right = Nil;
IsBlack = isBlack;
}
private void InsertFixup(RbtNode <T> node)
{
while (!node.Parent.IsBlack)
{
node = node.Parent == node.Parent.Parent.Left ? InsertLeftFixup(node) : InsertRightFixUp(node);
}
Head.IsBlack = true;
}
private static RbtNode <T> GetMaxNodeOrThrow(RbtNode <T> node)
{
if (node == RbtNode <T> .Nil)
{
throw new Exception("Tree is empty");
}
var current = node;
while (current.Right != RbtNode <T> .Nil)
{
current = current.Right;
}
return(current);
}
private static RbtNode <T> GetNextNode(RbtNode <T> node)
{
if (node.Right != RbtNode <T> .Nil)
{
return(GetMinNodeOrThrow(node.Right));
}
var tmp = node.Parent;
while (tmp != RbtNode <T> .Nil && node == tmp.Right)
{
node = tmp;
tmp = tmp.Parent;
}
return(tmp);
}
private void FixParent(RbtNode <T> lastNode, RbtNode <T> newNode)
{
if (lastNode.Parent == RbtNode <T> .Nil)
{
Head = newNode;
}
else if (lastNode == lastNode.Parent.Left)
{
lastNode.Parent.Left = newNode;
}
else
{
lastNode.Parent.Right = newNode;
}
}
public void RotateToRight(RbtNode <T> node)
{
var tmp = node.Left;
if (tmp == RbtNode <T> .Nil)
{
return;
}
node.Left = tmp.Right;
tmp.Right = node;
if (node.Left != RbtNode <T> .Nil)
{
node.Left.Parent = node;
}
FixParent(node, tmp);
tmp.Parent = node.Parent;
node.Parent = tmp;
}
public void RotateToLeft(RbtNode <T> node)
{
var tmp = node.Right;
if (tmp == RbtNode <T> .Nil || tmp.Value.CompareTo(node.Value) == 0)
{
return;
}
node.Right = tmp.Left;
tmp.Left = node;
if (node.Right != RbtNode <T> .Nil)
{
node.Right.Parent = node;
}
FixParent(node, tmp);
tmp.Parent = node.Parent;
node.Parent = tmp;
}
private RbtNode <T> InsertRightFixUp(RbtNode <T> node)
{
var tmp = node.Parent.Parent.Left;
if (!tmp.IsBlack)
{
node.Parent.IsBlack = true;
tmp.IsBlack = true;
node.Parent.Parent.IsBlack = false;
return(node.Parent.Parent);
}
if (node == node.Parent.Left)
{
RotateToRight(node = node.Parent);
}
node.Parent.IsBlack = true;
node.Parent.Parent.IsBlack = false;
RotateToLeft(node.Parent.Parent);
return(node);
}
//TODO: декомпозиция рефакторинг и все такое
private void RemoveFixUp(RbtNode <T> node)
{
while (node != Head && node.IsBlack)
{
if (node == node.Parent.Left)
{
var tmp = node.Parent.Right;
if (!tmp.IsBlack)
{
tmp.IsBlack = true;
node.Parent.IsBlack = false;
RotateToLeft(node.Parent);
tmp = node.Parent.Right;
}
if (tmp.Left.IsBlack && tmp.Right.IsBlack)
{
tmp.IsBlack = false;
node = node.Parent;
}
else
{
if (tmp.Right.IsBlack)
{
tmp.Left.IsBlack = true;
tmp.IsBlack = false;
RotateToRight(tmp);
tmp = node.Parent.Right;
}
tmp.IsBlack = node.Parent.IsBlack;
node.Parent.IsBlack = true;
tmp.Right.IsBlack = true;
RotateToLeft(node.Parent);
node = Head;
}
}
else
{
var tmp = node.Parent.Left;
if (!tmp.IsBlack)
{
tmp.IsBlack = true;
node.Parent.IsBlack = false;
RotateToRight(node.Parent);
tmp = node.Parent.Left;
}
if (tmp.Left.IsBlack && tmp.Right.IsBlack)
{
tmp.IsBlack = false;
node = node.Parent;
}
else
{
if (tmp.Left.IsBlack)
{
tmp.Right.IsBlack = true;
tmp.IsBlack = false;
RotateToLeft(tmp);
tmp = node.Parent.Left;
}
tmp.IsBlack = node.Parent.IsBlack;
node.Parent.IsBlack = true;
tmp.Left.IsBlack = true;
RotateToRight(node.Parent);
node = Head;
}
}
}
}
