/// <summary>
///getting enumerator
/// </summary>
/// <returns></returns>
public IEnumerator <KeyValuePair <TKey, TValue> > GetEnumerator()
{
if (RBroot != RBLeaf.Instance())
{
RBNode elem = RBroot;
Stack <RBNode> nodes = new Stack <RBNode>();
bool elemsOnLeft = true;
nodes.Push(elem);
while (nodes.Count > 0)
{
if (elemsOnLeft)
{
while (elem.left != RBLeaf.Instance())
{
nodes.Push(elem);
elem = elem.left;
}
}
yield return(new KeyValuePair <TKey, TValue>(elem.key, elem.value));
if (elem.right == RBLeaf.Instance())
{
elem = nodes.Pop();
elemsOnLeft = false;
}
else
{
elem = elem.right;
elemsOnLeft = true;
}
}
}
}
/// <summary>
/// searching minimum element in tree.
/// </summary>
/// <param name="elem"></param>
/// <returns></returns>
private RBNode RBMin(RBNode elem)
{
while (elem.left != RBLeaf.Instance())
{
elem = elem.right;
}
return(elem);
}
/// <summary>
/// adding key and value
/// </summary>
/// <param name="elemKey"></param>
/// <param name="elemVal"></param>
public void Add(TKey elemKey, TValue elemVal)
{
RBNode newNode = new RBNode();
newNode.key = elemKey;
newNode.value = elemVal;
newNode.left = RBLeaf.Instance();
newNode.right = RBLeaf.Instance();
Add(newNode);
count++;
entries.Add(newNode);
}
/// <summary>
/// Moving two nodes
/// </summary>
/// <param name="v1"></param>
/// <param name="v2"></param>
private void RBMove(RBNode v1, RBNode v2)
{
if (v1.parent == RBLeaf.Instance())
{
RBroot = v2;
}
else if (v1 == v1.parent.left)
{
v1.parent.left = v2;
}
else
{
v1.parent.right = v2;
}
v2.parent = v1.parent;
}
/// <summary>
/// adding node
/// </summary>
/// <param name="elem"></param>
private void Add(RBNode elem)
{
RBNode temp1 = RBLeaf.Instance();
RBNode temp2 = RBroot;
while (temp2 != RBLeaf.Instance())
{
temp1 = temp2;
if (elem.key.CompareTo(temp2.key) < 0)
{
temp2 = temp2.left;
}
else if (elem.key.CompareTo(temp2.key) > 0)
{
temp2 = temp2.right;
}
else if (elem.key.CompareTo(temp2.key) == 0)
{
return;
}
}
elem.parent = temp1;
if (temp1 == RBLeaf.Instance())
{
RBroot = elem;
}
else if (elem.key.CompareTo(temp1.key) < 0)
{
temp1.left = elem;
}
else if (elem.key.CompareTo(temp1.key) > 0)
{
temp1.right = elem;
}
else if (elem.key.CompareTo(temp1.key) == 0)
{
return;
}
elem.left = RBLeaf.Instance();
elem.right = RBLeaf.Instance();
elem.color = Color.red;
elem = RBFixInsertion(elem);
}
/// <summary>
/// deleting node
/// </summary>
/// <param name="elem"></param>
private void RBDelete(RBNode elem)
{
RBNode temp1;
RBNode temp2 = elem;
Color tempColor = temp2.color;
if (elem.left == RBLeaf.Instance())
{
temp1 = elem.right;
RBMove(elem, elem.right);
}
else if (elem.right == RBLeaf.Instance())
{
temp1 = elem.left;
RBMove(elem, elem.left);
}
else
{
temp2 = RBMin(elem.right);
tempColor = temp2.color;
temp1 = temp2.right;
if (temp2.parent == elem)
{
temp1.parent = temp2;
}
else
{
RBMove(temp1, temp2.right);
temp2.right = elem.right;
temp2.right.parent = temp2;
}
RBMove(elem, temp2);
temp2.left = elem.left;
temp2.left.parent = temp2;
temp2.color = elem.color;
}
if (tempColor == Color.black)
{
RBFixDeletion(temp1);
}
}
/// <summary>
/// Getting node with key
/// </summary>
/// <param name="elemKey"></param>
/// <returns></returns>
private RBNode GetNode(TKey elemKey)
{
RBNode node = RBroot;
while (node != RBLeaf.Instance())
{
if (elemKey.CompareTo(node.key) < 0)
{
node = node.left;
}
else if (elemKey.CompareTo(node.key) > 0)
{
node = node.right;
}
else
{
return(node);
}
}
return(null);
}
/// <summary>
/// parameterless constructor
/// </summary>
public RBTree()
{
RBroot = RBLeaf.Instance();
entries = new List <RBNode>(count);
}