public void RotateLeft_CheckColours()
{
RedBlackNode <int> node = new RedBlackNode <int>(100);
node.Right = new RedBlackNode <int>(150);
node = node.RotateLeft() as RedBlackNode <int>;
Assert.IsFalse(node.IsRed);
Assert.IsTrue(node.Left.IsRed);
}
public void RotateLeft_FullTree()
{
RedBlackNode <int> node = new RedBlackNode <int>(100);
node.Left = new RedBlackNode <int>(50);
node.Right = new RedBlackNode <int>(150);
node.Left.Left = new RedBlackNode <int>(25);
node.Left.Right = new RedBlackNode <int>(75);
node.Right.Left = new RedBlackNode <int>(125);
node.Right.Right = new RedBlackNode <int>(175);
node.ResetHeight();
node.Left.ResetHeight();
node.Right.ResetHeight();
node.Left.Left.ResetHeight();
node.Left.Right.ResetHeight();
node.Right.Left.ResetHeight();
node.Right.Right.ResetHeight();
node = node.RotateLeft() as RedBlackNode <int>;
Assert.AreEqual <int>(150, node.Value);
Assert.AreEqual <int>(175, node.Right.Value);
Assert.AreEqual <int>(100, node.Left.Value);
Assert.AreEqual <int>(125, node.Left.Right.Value);
Assert.AreEqual <int>(50, node.Left.Left.Value);
Assert.AreEqual <int>(25, node.Left.Left.Left.Value);
Assert.AreEqual <int>(75, node.Left.Left.Right.Value);
Assert.AreEqual <int>(3, node.Height);
Assert.AreEqual <int>(0, node.Right.Height);
Assert.AreEqual <int>(2, node.Left.Height);
Assert.AreEqual <int>(1, node.Left.Left.Height);
Assert.AreEqual <int>(0, node.Left.Right.Height);
Assert.AreEqual <int>(0, node.Left.Left.Left.Height);
Assert.AreEqual <int>(0, node.Left.Left.Right.Height);
}
public void RotateLeft_FullTree()
{
RedBlackNode<int> node = new RedBlackNode<int>(100);
node.Left = new RedBlackNode<int>(50);
node.Right = new RedBlackNode<int>(150);
node.Left.Left = new RedBlackNode<int>(25);
node.Left.Right = new RedBlackNode<int>(75);
node.Right.Left = new RedBlackNode<int>(125);
node.Right.Right = new RedBlackNode<int>(175);
node.ResetHeight();
node.Left.ResetHeight();
node.Right.ResetHeight();
node.Left.Left.ResetHeight();
node.Left.Right.ResetHeight();
node.Right.Left.ResetHeight();
node.Right.Right.ResetHeight();
node = node.RotateLeft() as RedBlackNode<int>;
Assert.AreEqual<int>(150, node.Value);
Assert.AreEqual<int>(175, node.Right.Value);
Assert.AreEqual<int>(100, node.Left.Value);
Assert.AreEqual<int>(125, node.Left.Right.Value);
Assert.AreEqual<int>(50, node.Left.Left.Value);
Assert.AreEqual<int>(25, node.Left.Left.Left.Value);
Assert.AreEqual<int>(75, node.Left.Left.Right.Value);
Assert.AreEqual<int>(3, node.Height);
Assert.AreEqual<int>(0, node.Right.Height);
Assert.AreEqual<int>(2, node.Left.Height);
Assert.AreEqual<int>(1, node.Left.Left.Height);
Assert.AreEqual<int>(0, node.Left.Right.Height);
Assert.AreEqual<int>(0, node.Left.Left.Left.Height);
Assert.AreEqual<int>(0, node.Left.Left.Right.Height);
}
public void RotateLeft_CheckColours()
{
RedBlackNode<int> node = new RedBlackNode<int>(100);
node.Right = new RedBlackNode<int>(150);
node = node.RotateLeft() as RedBlackNode<int>;
Assert.IsFalse(node.IsRed);
Assert.IsTrue(node.Left.IsRed);
}
/// <summary>
/// Corects tree.
/// </summary>
/// <param name="node">Start fom this node.</param>
private void RepairTree(RedBlackNode node)
{
if (node == this.rootNode)
{
return;
}
//if (node.ParentNode == null)//case1
//{
// this.rootNode = node;
// node.Color = NodeColor.BLACK;
//}
if (node.ParentNode.Color == NodeColor.BLACK)
{
return;
}
if (node.Uncle != null && node.Uncle.Color == NodeColor.RED)
{
//What if Uncle == null
node.ParentNode.Color = NodeColor.BLACK;
node.Uncle.Color = NodeColor.BLACK;
node.Grandparent.Color = NodeColor.RED;
RepairTree(node.Grandparent);
return;
} //case 3
else //case 4
{
RedBlackNode p = node.ParentNode;
RedBlackNode g = node.Grandparent;
if (p == g.RightNode)
{
if (node == p.RightNode)
{
g.RotateLeft();
if (p.ParentNode == null)
{
this.rootNode = p;
}
return;
}
node.ParentNode.RotateRight();
node.ParentNode.RotateLeft();
if (node == null)
{
this.rootNode = node;
}
return;
}
if (node == p.LeftNode)
{
g.RotateRight();
if (p.ParentNode == null)
{
this.rootNode = p;
}
return;
}
node.ParentNode.RotateLeft();
node.ParentNode.RotateRight();
if (node == null)
{
this.rootNode = node;
}
return;
}//case4
}
/// <summary>
/// Removes the elemet from tree.
/// </summary>
/// <param name="item">Key Value pair of the elemet.</param>
/// <returns>True if removed.</returns>
public bool Remove(KeyValuePair <TKey, TValue> item)
{
RedBlackNode temp = this.rootNode;
while (temp != null)
{
switch (item.Key.CompareTo(temp.NodeKey))
{
case -1:
temp = temp.LeftNode;
break;
case 1:
temp = temp.RightNode;
break;
default:
{
if (temp.IsLeaf)
{
if (temp.ParentNode.LeftNode == temp)
{
temp.ParentNode.LeftNode = null;
this.RepairTree(temp.ParentNode);
nodeCount--;
isModfied = true;
return(true);
}
temp.ParentNode.RightNode = null;
this.RepairTree(temp.ParentNode);
nodeCount--;
isModfied = true;
return(true);
}
else if (temp.LeftNode == null)
{
temp.RightNode.ParentNode = temp.ParentNode;
if (temp.ParentNode.LeftNode == temp)
{
temp.ParentNode.LeftNode = temp.RightNode;
this.RepairTree(temp.ParentNode);
nodeCount--;
isModfied = true;
return(true);
}
temp.ParentNode.RightNode = null;
this.RepairTree(temp.ParentNode);
nodeCount--;
isModfied = true;
return(true);
}
else if (temp.RightNode == null)
{
temp.LeftNode.ParentNode = temp.ParentNode;
if (temp.ParentNode.LeftNode == temp)
{
temp.ParentNode.LeftNode = temp.LeftNode;
this.RepairTree(temp.ParentNode);
nodeCount--;
isModfied = true;
return(true);
}
temp.ParentNode.RightNode = null;
this.RepairTree(temp.ParentNode);
nodeCount--;
isModfied = true;
return(true);
}
else
{
temp.RotateLeft();
temp.ParentNode.LeftNode = temp.LeftNode;
temp.LeftNode.ParentNode = temp.ParentNode;
this.RepairTree(temp.ParentNode);
nodeCount--;
isModfied = true;
return(true);
}
}
}
}
return(false);
}