private RBTreeNode <T> TreeSuccessor(RBTreeNode <T> T)
{
if (T == this.tree.NIL)
{
return(null);
}
if (T.Right != this.tree.NIL)
{
return(this.TreeMinimum(T.Right));
}
RBTreeNode <T> parent = T.Parent;
while (parent != null && T == parent.Right)
{
T = parent;
parent = parent.Parent;
}
return(parent);
}
private bool IsBlack(RBTreeNode <T> T)
{
return(T.Color == RBTreeNode <T> .COLOR.BLACK);
}
private bool IsRed(RBTreeNode <T> T)
{
return(T.Color == RBTreeNode <T> .COLOR.RED);
}
private void RBDeleteFixUp(RBTreeNode <T> x)
{
while (x != this.tree.root && x.IsBlack())
{
if (x == x.Parent.Left)
{
RBTreeNode <T> right = x.Parent.Right;
if (right.IsRed())
{
right.Color = RBTreeNode <T> .COLOR.BLACK;
x.Parent.Color = RBTreeNode <T> .COLOR.RED;
this.RotateLeft(x.Parent);
right = x.Parent.Right;
}
if (right.Left.IsBlack() && right.Right.IsBlack())
{
right.Color = RBTreeNode <T> .COLOR.RED;
x = x.Parent;
}
else
{
if (right.Right.IsBlack())
{
right.Left.Color = RBTreeNode <T> .COLOR.BLACK;
right.Color = RBTreeNode <T> .COLOR.RED;
this.RotateRight(right);
right = x.Parent.Right;
}
right.Color = x.Parent.Color;
x.Parent.Color = RBTreeNode <T> .COLOR.BLACK;
right.Right.Color = RBTreeNode <T> .COLOR.BLACK;
this.RotateLeft(x.Parent);
x = this.tree.root;
}
}
else
{
RBTreeNode <T> left = x.Parent.Left;
if (left.IsRed())
{
left.Color = RBTreeNode <T> .COLOR.BLACK;
x.Parent.Color = RBTreeNode <T> .COLOR.RED;
this.RotateRight(x.Parent);
left = x.Parent.Left;
}
if (left.Right.IsBlack() && left.Left.IsBlack())
{
left.Color = RBTreeNode <T> .COLOR.RED;
x = x.Parent;
}
else
{
if (left.Left.IsBlack())
{
left.Right.Color = RBTreeNode <T> .COLOR.BLACK;
left.Color = RBTreeNode <T> .COLOR.RED;
this.RotateRight(left);
left = x.Parent.Left;
}
left.Color = x.Parent.Color;
x.Parent.Color = RBTreeNode <T> .COLOR.BLACK;
left.Left.Color = RBTreeNode <T> .COLOR.BLACK;
this.RotateRight(x.Parent);
x = this.tree.root;
}
}
}
x.Color = RBTreeNode <T> .COLOR.BLACK;
}
public void Delete(T i)
{
RBTreeNode <T> z = this.Search(this.tree.root, i);
this.RBDelete(z);
}
private void CheckBalance()
{
if (!this.IsRoot() && this.Parent.IsRed())
{
if (this.IsFatherLeftofGrandFather())
{
RBTreeNode <T> rightUncle = this.GetRightUncle();
if (rightUncle != this.tree.NIL && rightUncle != null && rightUncle.IsRed())
{
this.ColorGrandFather(RBTreeNode <T> .COLOR.RED);
rightUncle.Color = RBTreeNode <T> .COLOR.BLACK;
this.Parent.Color = RBTreeNode <T> .COLOR.BLACK;
RBTreeNode <T> grandFather = this.GetGrandFather();
if (grandFather != null)
{
grandFather.CheckBalance();
}
}
else
{
if (this == this.Parent.Right)
{
this.RotateLeft(this.Parent);
}
this.ColorFather(RBTreeNode <T> .COLOR.BLACK);
this.ColorGrandFather(RBTreeNode <T> .COLOR.RED);
if (this.Parent.Parent != null)
{
this.RotateRight(this.Parent.Parent);
}
}
}
else
{
RBTreeNode <T> leftUncle = this.GetLeftUncle();
if (leftUncle != this.tree.NIL && leftUncle != null && leftUncle.IsRed())
{
this.ColorGrandFather(RBTreeNode <T> .COLOR.RED);
leftUncle.Color = RBTreeNode <T> .COLOR.BLACK;
this.Parent.Color = RBTreeNode <T> .COLOR.BLACK;
RBTreeNode <T> grandFather2 = this.GetGrandFather();
if (grandFather2 != null)
{
grandFather2.CheckBalance();
}
}
else
{
if (this == this.Parent.Left)
{
this.RotateRight(this.Parent);
}
this.ColorFather(RBTreeNode <T> .COLOR.BLACK);
this.ColorGrandFather(RBTreeNode <T> .COLOR.RED);
if (this.Parent.Parent != null)
{
this.RotateLeft(this.Parent.Parent);
}
}
}
}
this.tree.root.Color = RBTreeNode <T> .COLOR.BLACK;
}
private bool IsRoot(RBTreeNode <T> T)
{
return(T.Parent == null);
}
public RedBlackTree()
{
this.NIL = RBTreeNode <T> .MakeNilNode(this);
this.root = null;
}
public void Delete(T i)
{
RBTreeNode <T> z = Search(tree.root, i);
RBDelete(z);
}
private void CheckBalance()
{
if (!IsRoot() && Parent.IsRed())
{
if (IsFatherLeftofGrandFather())
{
RBTreeNode <T> rightUncle = GetRightUncle();
if (rightUncle != tree.NIL && rightUncle != null && rightUncle.IsRed())
{
ColorGrandFather(COLOR.RED);
rightUncle.Color = COLOR.BLACK;
Parent.Color = COLOR.BLACK;
RBTreeNode <T> grandFather = GetGrandFather();
if (grandFather != null)
{
grandFather.CheckBalance();
}
}
else
{
if (this == Parent.Right)
{
RotateLeft(Parent);
}
ColorFather(COLOR.BLACK);
ColorGrandFather(COLOR.RED);
if (Parent.Parent != null)
{
RotateRight(Parent.Parent);
}
}
}
else
{
RBTreeNode <T> leftUncle = GetLeftUncle();
if (leftUncle != tree.NIL && leftUncle != null && leftUncle.IsRed())
{
ColorGrandFather(COLOR.RED);
leftUncle.Color = COLOR.BLACK;
Parent.Color = COLOR.BLACK;
RBTreeNode <T> grandFather2 = GetGrandFather();
if (grandFather2 != null)
{
grandFather2.CheckBalance();
}
}
else
{
if (this == Parent.Left)
{
RotateRight(Parent);
}
ColorFather(COLOR.BLACK);
ColorGrandFather(COLOR.RED);
if (Parent.Parent != null)
{
RotateLeft(Parent.Parent);
}
}
}
}
tree.root.Color = COLOR.BLACK;
}