private IEnumerable <T> PreOrderTraversalHelper(
MyBinarySearchTreeNode <T> root)
{
if (root == null)
{
yield break;
}
yield return(root.Data);
List <T> data = new List <T>();
if (root.Left != null)
{
data.AddRange(PreOrderTraversalHelper(root.Left));
}
if (root.Right != null)
{
data.AddRange(PreOrderTraversalHelper(root.Right));
}
foreach (var item in data)
{
yield return(item);
}
}
private MyBinarySearchTreeNode <T> FindSmallestNodeInRightSubTree(
MyBinarySearchTreeNode <T> root)
{
if (root == null)
{
return(root);
}
var node = FindSmallestNodeInRightSubTree(root.Left);
return(node ?? root);
}
private MyBinarySearchTreeNode <T> FindLargestNodeInLeftSubStree(MyBinarySearchTreeNode <T> root)
{
if (root == null)
{
return(root);
}
var node = FindLargestNodeInLeftSubStree(root.Right);
return(node ?? root);
}
public virtual void Insert(T data)
{
if (Root == null)
{
Root = new MyBinarySearchTreeNode <T>(data);
}
else
{
InsertHelper(data, Root);
}
Count++;
}
private void InsertHelper(T data, MyBinarySearchTreeNode <T> root)
{
var compared = data.CompareTo(root.Data);
if (compared == 0)
{
var node = new MyBinarySearchTreeNode <T>(data);
if (root.Left != null)
{
node.Left = root.Left;
node.Right = root.Left.Right;
root.Left = node;
}
else
{
root.Left = node;
}
}
if (compared < 0)
{
if (root.Left == null)
{
root.Left = new MyBinarySearchTreeNode <T>(data);
}
else
{
InsertHelper(data, root.Left);
}
}
if (compared > 0)
{
if (root.Right == null)
{
root.Right = new MyBinarySearchTreeNode <T>(data);
}
else
{
InsertHelper(data, root.Right);
}
}
}
private bool ContainsHelper(MyBinarySearchTreeNode <T> node,
T data)
{
if (node == null)
{
return(false);
}
if (node.Data.Equals(data))
{
return(true);
}
if (ContainsHelper(node.Left, data))
{
return(true);
}
if (ContainsHelper(node.Right, data))
{
return(true);
}
return(false);
}
public MyBinarySearchTreeNode(T data, MyBinarySearchTreeNode <T> left,
MyBinarySearchTreeNode <T> right) : this(data)
{
Left = left;
Right = right;
}
private bool RemoveHelper(MyBinarySearchTreeNode <T> root,
MyBinarySearchTreeNode <T> parent, T data)
{
if (root == null)
{
return(false);
}
if (root.Data.Equals(data))
{
if (root.Left == null && root.Right == null)
{
if (parent.Left != null && parent.Left.Data.Equals(root.Data))
{
parent.Left = null;
}
else
{
parent.Right = null;
}
return(true);
}
if (root.Left != null && root.Right == null)
{
if (parent.Right != null && parent.Right.Data.Equals(root.Data))
{
parent.Right = root.Left;
}
else
{
parent.Left = root.Left;
}
return(true);
}
if (root.Right != null && root.Left == null)
{
if (parent.Right != null && parent.Right.Data.Equals(root.Data))
{
parent.Right = root.Right;
}
else
{
parent.Left = root.Right;
}
return(true);
}
if (root.Right != null && root.Left != null)
{
var swapNode = FindLargestNodeInLeftSubStree(root.Left) ??
FindSmallestNodeInRightSubTree(root.Right);
var temp = swapNode.Data;
swapNode.Data = root.Data;
root.Data = temp;
return(RemoveHelper(Root, null, swapNode.Data));
}
}
if (RemoveHelper(root.Left, root, data))
{
return(true);
}
if (RemoveHelper(root.Right, root, data))
{
return(true);
}
return(false);
}