private void RotateRight(RbNode <T> x)
{
var y = x.Left;
x.Left = y.Right;
if (y.Right != TNull)
{
y.Right.Parent = x;
}
y.Parent = x.Parent;
if (x.Parent != null)
{
if (x == x.Parent.Right)
{
x.Parent.Right = y;
}
else
{
x.Parent.Left = y;
}
}
else
{
Root = y;
}
y.Right = x;
x.Parent = y;
}
private void InsertFix(RbNode <T> x)
{
while (x != Root && x.Parent.Red)
{
RbNode <T> y;
if (x.Parent == x.Parent.Parent.Left)
{
y = x.Parent.Parent.Right;
if (y.Red)
{
x.Parent.Red = false;
y.Red = false;
x.Parent.Parent.Red = true;
x = x.Parent.Parent;
}
else
{
if (x == x.Parent.Right)
{
x = x.Parent;
RotateLeft(x);
}
x.Parent.Red = false;
x.Parent.Parent.Red = true;
RotateRight(x.Parent.Parent);
}
}
else
{
y = x.Parent.Parent.Left;
if (y.Red)
{
x.Parent.Red = false;
y.Red = false;
x.Parent.Parent.Red = true;
x = x.Parent.Parent;
}
else
{
if (x == x.Parent.Left)
{
x = x.Parent;
RotateRight(x);
}
x.Parent.Red = false;
x.Parent.Parent.Red = true;
RotateLeft(x.Parent.Parent);
}
}
}
Root.Red = false;
}
private int GetHeight(RbNode <T> x)
{
if (x == null || x == TNull)
{
return(-1);
}
var a = GetHeight(x.Left);
var b = GetHeight(x.Right);
return(a > b ? a + 1 : b + 1);
}
public RbNode <T> Find(T key)
{
var current = Root;
while (current != TNull)
{
if (RbNode <T> .IsEqualTo(key, current.Key))
{
return(current);
}
current = RbNode <T> .IsGreaterThan(key, current.Key) ? current.Right : current.Left;
}
return(null);
}
private void RemoveFix(RbNode <T> x)
{
while (x != Root && !x.Red)
{
if (x == x.Parent.Left)
{
var w = x.Parent.Right;
if (w.Red)
{
w.Red = false;
x.Parent.Red = true;
RotateLeft(x.Parent);
w = x.Parent.Right;
}
if (!w.Left.Red && !w.Right.Red)
{
w.Red = true;
x = x.Parent;
}
else
{
if (!w.Right.Red)
{
w.Left.Red = false;
w.Red = true;
RotateRight(w);
w = x.Parent.Right;
}
w.Red = x.Parent.Red;
x.Parent.Red = false;
w.Right.Red = false;
RotateLeft(x.Parent);
x = Root;
}
}
else
{
var w = x.Parent.Left;
if (w.Red)
{
w.Red = false;
x.Parent.Red = true;
RotateRight(x.Parent);
w = x.Parent.Left;
}
if (!w.Right.Red && !w.Left.Red)
{
w.Red = true;
x = x.Parent;
}
else
{
if (!w.Left.Red)
{
w.Right.Red = false;
w.Red = true;
RotateLeft(w);
w = x.Parent.Left;
}
w.Red = x.Parent.Red;
x.Parent.Red = false;
w.Left.Red = false;
RotateRight(x.Parent);
x = Root;
}
}
}
x.Red = false;
}
