static void PrintRB(RBTreeNode node, int l)
{
int i;
if (node != null)
{
PrintRB(node.right, l + 1);
for (i = 0; i < l; i++)
{
Console.Write(" ");
}
Console.Write(node);
PrintRB(node.left, l + 1);
}
else
{
Console.WriteLine();
}
}
public void InsertFixUp(RBTreeNode node)
{
var parentnode = node.parent;
if (parentnode != null && parentnode.color == Color.red)
{
var gparent = parentnode.parent;
if (parentnode == gparent.left)
{
var unclenode = gparent.right;
if (unclenode != null && unclenode.color == Color.red)
{
setRed(gparent);
setBlack(parentnode);
setBlack(unclenode);
InsertFixUp(gparent);
}
else
{
if (node == parentnode.left)
{
setBlack(parentnode);
setRed(gparent);
Rightrotate(gparent);
}
else if (node == parentnode.right)
{
LeftRotate(parentnode);
InsertFixUp(parentnode);
}
}
}
else
{
var unclenode = gparent.left;
if (unclenode != null && unclenode.color == Color.red)
{
setBlack(parentnode);
setBlack(unclenode);
setRed(gparent);
InsertFixUp(gparent);
}
else
{
if (node == parentnode.right)
{
setBlack(parentnode);
setRed(gparent);
LeftRotate(gparent);
}
else if (node == parentnode.left)
{
Rightrotate(parentnode);
InsertFixUp(parentnode);
}
}
}
}
setBlack(rootnode);
}
public void setRed(RBTreeNode node)
{
node.color = Color.red;
}
public void setBlack(RBTreeNode node)
{
node.color = Color.black;
}
private void removeFix(RBTreeNode node, RBTreeNode parent)
{
RBTreeNode other;
while ((node == null || node.color == Color.black) && node != rootnode)
{
if (parent.left == node)
{//One, node is the left child node
other = parent.right;
if (other.color != Color.black)
{//1.node's sibling node other is red
other.color = Color.black;
parent.color = Color.red;
LeftRotate(parent);
other = parent.right;
}
if ((other.left == null || other.left.color == Color.black) && (other.right == null || other.right.color == Color.black))
{//2. The sibling node other of node is black, and the two child nodes of other are also black
other.color = Color.red;
node = parent;
parent = node.parent;
}
else
{//3. The sibling node other of node is black, and the left child node of other is red, and the right child node is black
if (other.right == null || other.right.color == Color.black)
{
other.left.color = Color.black;
other.color = Color.red;
Rightrotate(other);
other = parent.right;
}
//4. The sibling node of node is black, and the right child node of other is red, and the left child node is any color
other.color = parent.color;
parent.color = Color.black;
other.right.color = Color.black;
LeftRotate(parent);
node = this.rootnode;
break;
}
}
else
{
other = parent.left;
if (other.color == Color.red)
{
other.color = Color.black;
parent.color = Color.red;
Rightrotate(parent);
other = parent.left;
}
if ((other.left == null || other.left.color == Color.black) && (other.right == null || other.right.color == Color.black))
{
other.color = Color.red;
node = parent;
parent = node.parent;
}
else
{
if (other.left == null || other.left.color == Color.black)
{
other.right.color = Color.black;
other.color = Color.red;
LeftRotate(other);
other = parent.left;
}
other.color = parent.color;
parent.color = Color.black;
other.left.color = Color.black;
Rightrotate(parent);
node = rootnode;
break;
}
}
}
if (node != null)
{
node.color = Color.black;
}
}
public bool remove(Date key)
{
RBTreeNode node;
node = find(key);
if (node == null)
{
return(false);
}
RBTreeNode child, parent;
Count--;
Color color;
if (node.left == null && node.right == null)
{//No child nodes
if (node == rootnode)
{
rootnode = null;
return(true);
}
if (node.parent.left == node)
{
node.parent.left = null;
}
else
{
node.parent.right = null;
}
return(true);
}
if ((node.left != null) && (node.right != null))
{//There are two child nodes
//1. Get subsequent nodes
RBTreeNode replace = node;
replace = replace.right;
while (replace.left != null)
{
replace = replace.left;
}
//2. Connect parent node and successor node
if (node.parent != null)
{
if (node == node.parent.left)
{
node.parent.left = replace;
}
else
{
node.parent.right = replace;
}
}
else
{//If it is the root node
rootnode = replace;
}
//3. Dealing with relationship issues
child = replace.right;
parent = replace.parent;
color = replace.color;
if (parent == node)
{//The successor is the child node of the deleted node
parent = replace;
}
else
{
if (child != null)
{
child.parent = parent;
}
parent.left = child;
replace.right = node.right;
node.right.parent = replace;
}
replace.parent = node.parent;
replace.color = node.color;
replace.left = node.left;
node.left.parent = replace;
//4. The subsequent node is black, then the red-black tree needs to be corrected
if (color == Color.black)
{
removeFix(child, parent);
}
node = null;
return(true);
}
else
{
if (node.left == null)
{
if (node == rootnode)
{
rootnode = node.right;
node.parent = null;
return(true);
}
if (node.parent.left == node)
{
node.parent.left = node.right;
}
else
{
node.parent.right = node.right;
}
node.right.parent = node.parent;
if (node.color == Color.black)
{
removeFix(node.right, node.right.parent);
}
node = null;
}
else
{
if (node == rootnode)
{
rootnode = node.left;
node.parent = null;
return(true);
}
if (node.parent.left == node)
{
node.parent.left = node.left;
}
else
{
node.parent.right = node.left;
}
node.left.parent = node.parent;
if (node.color == Color.black)
{
removeFix(node.left, node.left.parent);
}
node = null;
}
return(true);
}
}
