//public ThreadedBinaryTree(TBTNode root)
//{
// this.Root = root;
//}
/// <summary>
/// Insert keys into BST
/// </summary>
/// <param name="nodePointer"></param>
/// <param name="key"></param>
/// <returns></returns>
public static TBTNode InsertKey(TBTNode nodePointer, int key)
{
if (nodePointer is null)
{
TBTNode root = new TBTNode(key);
return(root);
}
if (key < nodePointer.Key)
{
if (nodePointer.Left is null)
{
nodePointer.Left = new TBTNode(key);
}
else
{
InsertKey(nodePointer.Left, key);
}
}
else
{
if (nodePointer.Right is null)
{
nodePointer.Right = new TBTNode(key);
}
else
{
InsertKey(nodePointer.Right, key);
}
}
return(nodePointer);
}
/// <summary>
/// Create Threaded BST i.e. TBT
/// </summary>
/// <param name="root"></param>
/// <returns></returns>
public static TBTNode CreateThreadedBST(TBTNode root)
{
// root is null, just get out
if (root is null)
{
return(null);
}
// root is the only node
if (root.Left is null && root.Right is null)
{
return(root);
}
// Find predecessor, if any
if (root.Left != null)
{
// Find predecessor of root (Rightmost
// child in left subtree)
TBTNode tNode = CreateThreadedBST(root.Left);
// Link a thread from predecessor to root.
tNode.Next = root;
}
// If node is the rightmost child
if (root.Right is null)
{
return(root);
}
// Recur for right subtree
return(CreateThreadedBST(root.Right));
}
private static TBTNode LeftMostNode(TBTNode node)
{
while (node != null && node.Left != null)
{
node = node.Left;
}
return(node);
}
/// <summary>
/// InOrder traversal of the BST
/// </summary>
/// <param name="node"></param>
public static void TraverseInOrder(TBTNode node)
{
if (node is null)
{
return;
}
// In-order traversal of the tree to return an ordered list of nodes
if (node.Left != null)
{
TraverseInOrder(node.Left);
}
Console.Write($"{node.Key} ");
if (node.Right != null)
{
TraverseInOrder(node.Right);
}
}
/// <summary>
/// Create ordered queue of the tree nodes in ascending order; can ignore this queue for now; not used
/// </summary>
/// <param name="qNodes"></param>
/// <param name="node"></param>
/// <returns></returns>
public static Queue <TBTNode> CreateQueue(Queue <TBTNode> qNodes, TBTNode node)
{
if (node is null)
{
return(null);
}
// In-order traversal of the tree to return an ordered list of nodes for the queue
if (node.Left != null)
{
CreateQueue(qNodes, node.Left);
}
qNodes.Enqueue(node);
if (node.Right != null)
{
CreateQueue(qNodes, node.Right);
}
return(qNodes);
}
/// <summary>
/// Traverse TBT - from leftmost child
/// </summary>
/// <param name="node"></param>
public static void TraverseTBTInOrder(TBTNode node)
{
if (node is null)
{
return;
}
TBTNode current = LeftMostNode(node);
while (current != null)
{
Console.Write($"{current.Key} ");
if (current.Next != null)
{
current = current.Next;
}
else
{
current = LeftMostNode(current.Right);
}
}
}
