void Replace(TreeSegment oldNode, TreeSegment newNode)
{
if (newNode != null)
{
newNode.Parent = oldNode.Parent;
}
if (oldNode.Parent == null)
{
Root = (T)newNode;
}
else
{
if (oldNode.Parent.Left == oldNode)
{
oldNode.Parent.Left = newNode;
}
else
{
oldNode.Parent.Right = newNode;
}
oldNode.Parent.UpdateAugmentedData();
}
}
void DeleteOneChild(TreeSegment node)
{
// case 1
if (node == null || node.Parent == null)
{
return;
}
var parent = node.Parent;
var sibling = node.Sibling;
if (sibling == null)
{
return;
}
// case 2
if (sibling.Color == Red)
{
parent.Color = Red;
sibling.Color = Black;
if (node == parent.Left)
{
RotateLeft(parent);
}
else
{
RotateRight(parent);
}
sibling = node.Sibling;
if (sibling == null)
{
return;
}
}
// case 3
if (parent.Color == Black && sibling.Color == Black && GetColorSafe(sibling.Left) == Black && GetColorSafe(sibling.Right) == Black)
{
sibling.Color = Red;
DeleteOneChild(parent);
return;
}
// case 4
if (parent.Color == Red && sibling.Color == Black && GetColorSafe(sibling.Left) == Black && GetColorSafe(sibling.Right) == Black)
{
sibling.Color = Red;
parent.Color = Black;
return;
}
// case 5
if (node == parent.Left && sibling.Color == Black && GetColorSafe(sibling.Left) == Red && GetColorSafe(sibling.Right) == Black)
{
sibling.Color = Red;
if (sibling.Left != null)
{
sibling.Left.Color = Black;
}
RotateRight(sibling);
}
else if (node == parent.Right && sibling.Color == Black && GetColorSafe(sibling.Right) == Red && GetColorSafe(sibling.Left) == Black)
{
sibling.Color = Red;
if (sibling.Right != null)
{
sibling.Right.Color = Black;
}
RotateLeft(sibling);
}
// case 6
sibling = node.Sibling;
if (sibling == null)
{
return;
}
sibling.Color = parent.Color;
parent.Color = Black;
if (node == parent.Left)
{
if (sibling.Right != null)
{
sibling.Right.Color = Black;
}
RotateLeft(parent);
}
else
{
if (sibling.Left != null)
{
sibling.Left.Color = Black;
}
RotateRight(parent);
}
}
static bool GetColorSafe(TreeSegment node)
{
return(node != null ? node.Color : Black);
}
bool TextSegmentTree.Remove(TreeSegment segment)
{
return(InternalRemove(segment));
}
void TextSegmentTree.Add(TreeSegment segment)
{
InternalAdd(segment);
}
