public RedBlackEnumerator(RedBlack redBlack, RedBlackNode tnode, bool keys, bool ascending)
{
this.stack = new Stack();
this.keys = keys;
this.ascending = ascending;
this.redBlack = redBlack;
if(ascending)
{
while (tnode != redBlack.sentinelNode)
{
stack.Push(tnode);
tnode = tnode.Left;
}
}
else
{
while (tnode != redBlack.sentinelNode)
{
stack.Push(tnode);
tnode = tnode.Right;
}
}
}
private void RestoreAfterInsert(RedBlackNode x)
{
RedBlackNode y;
while(x != rbTree && x.Parent.Color == RedBlackNode.RED)
{
if(x.Parent == x.Parent.Parent.Left)
{
y = x.Parent.Parent.Right;
if(y!= null && y.Color == RedBlackNode.RED)
{
x.Parent.Color = RedBlackNode.BLACK;
y.Color = RedBlackNode.BLACK;
x.Parent.Parent.Color = RedBlackNode.RED;
x = x.Parent.Parent;
}
else
{
if(x == x.Parent.Right)
{
x = x.Parent;
RotateLeft(x);
}
x.Parent.Color = RedBlackNode.BLACK;
x.Parent.Parent.Color = RedBlackNode.RED;
RotateRight(x.Parent.Parent);
}
}
else
{
y = x.Parent.Parent.Left;
if(y!= null && y.Color == RedBlackNode.RED)
{
x.Parent.Color = RedBlackNode.BLACK;
y.Color = RedBlackNode.BLACK;
x.Parent.Parent.Color = RedBlackNode.RED;
x = x.Parent.Parent;
}
else
{
if(x == x.Parent.Left)
{
x = x.Parent;
RotateRight(x);
}
x.Parent.Color = RedBlackNode.BLACK;
x.Parent.Parent.Color = RedBlackNode.RED;
RotateLeft(x.Parent.Parent);
}
}
}
rbTree.Color = RedBlackNode.BLACK;
}
public RedBlack()
{
strIdentifier = base.ToString() + rand.Next();
intHashCode = rand.Next();
sentinelNode = new RedBlackNode();
sentinelNode.Left = null;
sentinelNode.Right = null;
sentinelNode.Parent = null;
sentinelNode.Color = RedBlackNode.BLACK;
rbTree = sentinelNode;
lastNodeFound = sentinelNode;
}
public void Add(IComparable key, object data)
{
if(key == null || data == null)
throw(new RedBlackException("RedBlackNode key and data must not be null"));
int result = 0;
RedBlackNode node = new RedBlackNode();
RedBlackNode temp = rbTree; ;
while(temp != sentinelNode)
{
node.Parent = temp;
result = key.CompareTo(temp.Key);
if(result == 0)
throw(new RedBlackException("A Node with the same key already exists"));
if(result > 0)
temp = temp.Right;
else
temp = temp.Left;
}
node.Key = key;
node.Data = data;
node.Left = sentinelNode;
node.Right = sentinelNode;
if(node.Parent != null)
{
result = node.Key.CompareTo(node.Parent.Key);
if(result > 0)
node.Parent.Right = node;
else
node.Parent.Left = node;
}
else
rbTree = node;
RestoreAfterInsert(node);
lastNodeFound = node;
intCount = intCount + 1;
}
public void Clear ()
{
rbTree = sentinelNode;
intCount = 0;
}
private void RestoreAfterDelete(RedBlackNode x)
{
RedBlackNode y;
while(x != rbTree && x.Color == RedBlackNode.BLACK)
{
if(x == x.Parent.Left)
{
y = x.Parent.Right;
if(y.Color == RedBlackNode.RED)
{
y.Color = RedBlackNode.BLACK;
x.Parent.Color = RedBlackNode.RED;
RotateLeft(x.Parent);
y = x.Parent.Right;
}
if(y.Left.Color == RedBlackNode.BLACK &&
y.Right.Color == RedBlackNode.BLACK)
{
y.Color = RedBlackNode.RED;
x = x.Parent;
}
else
{
if(y.Right.Color == RedBlackNode.BLACK)
{
y.Left.Color = RedBlackNode.BLACK;
y.Color = RedBlackNode.RED;
RotateRight(y);
y = x.Parent.Right;
}
y.Color = x.Parent.Color;
x.Parent.Color = RedBlackNode.BLACK;
y.Right.Color = RedBlackNode.BLACK;
RotateLeft(x.Parent);
x = rbTree;
}
}
else
{
y = x.Parent.Left;
if(y.Color == RedBlackNode.RED)
{
y.Color = RedBlackNode.BLACK;
x.Parent.Color = RedBlackNode.RED;
RotateRight (x.Parent);
y = x.Parent.Left;
}
if(y.Right.Color == RedBlackNode.BLACK &&
y.Left.Color == RedBlackNode.BLACK)
{
y.Color = RedBlackNode.RED;
x = x.Parent;
}
else
{
if(y.Left.Color == RedBlackNode.BLACK)
{
y.Right.Color = RedBlackNode.BLACK;
y.Color = RedBlackNode.RED;
RotateLeft(y);
y = x.Parent.Left;
}
y.Color = x.Parent.Color;
x.Parent.Color = RedBlackNode.BLACK;
y.Left.Color = RedBlackNode.BLACK;
RotateRight(x.Parent);
x = rbTree;
}
}
}
x.Color = RedBlackNode.BLACK;
}
private void Delete(RedBlackNode z)
{
RedBlackNode x = new RedBlackNode();
RedBlackNode y;
if(z.Left == sentinelNode || z.Right == sentinelNode)
y = z;
else
{
y = z.Right;
while(y.Left != sentinelNode)
y = y.Left;
}
if(y.Left != sentinelNode)
x = y.Left;
else
x = y.Right;
x.Parent = y.Parent;
if(y.Parent != null)
if(y == y.Parent.Left)
y.Parent.Left = x;
else
y.Parent.Right = x;
else
rbTree = x;
if(y != z)
{
z.Key = y.Key;
z.Data = y.Data;
}
if(y.Color == RedBlackNode.BLACK)
RestoreAfterDelete(x);
lastNodeFound = sentinelNode;
}
public IComparable GetMaxKey()
{
RedBlackNode treeNode = rbTree;
if(treeNode == null || treeNode == sentinelNode)
throw(new RedBlackException("RedBlack tree is empty"));
while(treeNode.Right != sentinelNode)
treeNode = treeNode.Right;
lastNodeFound = treeNode;
return treeNode.Key;
}
public bool TryGetValue(IComparable key, out object value)
{
int result;
value = null;
var keyFound = false;
RedBlackNode treeNode = rbTree;
while(treeNode != sentinelNode)
{
result = key.CompareTo(treeNode.Key);
if(result == 0)
{
lastNodeFound = treeNode;
value = treeNode.Data;
keyFound = true;
break;
}
if(result < 0)
treeNode = treeNode.Left;
else
treeNode = treeNode.Right;
}
return keyFound;
}
public void RotateRight(RedBlackNode x)
{
RedBlackNode y = x.Left;
x.Left = y.Right;
if(y.Right != sentinelNode)
y.Right.Parent = x;
if(y != sentinelNode)
y.Parent = x.Parent;
if(x.Parent != null)
{
if(x == x.Parent.Right)
x.Parent.Right = y;
else
x.Parent.Left = y;
}
else
rbTree = y;
y.Right = x;
if(x != sentinelNode)
x.Parent = y;
}
