public void Remove(int value)
{
if (this.rootNode == null)
{
return;
}
var currentNode = this.rootNode;
BinaryNode parentNode = new BinaryNode();
while (currentNode != null)
{
if (value < currentNode.Value)
{
parentNode = currentNode;
currentNode = currentNode.LeftNode;
}
else if (value > currentNode.Value)
{
parentNode = currentNode;
currentNode = currentNode.RightNode;
}
else if (currentNode.Value == value)
{
if (currentNode.RightNode == null)
{
if (parentNode == null)
{
this.rootNode = currentNode.LeftNode;
}
else
{
if (currentNode.Value < parentNode.Value)
{
parentNode.LeftNode = currentNode.LeftNode;
}
else if (currentNode.Value > parentNode.Value)
{
parentNode.RightNode = currentNode.LeftNode;
}
}
}
else if (currentNode.RightNode.LeftNode == null)
{
if (parentNode == null)
{
this.rootNode = currentNode.LeftNode;
}
else
{
currentNode.RightNode.LeftNode = currentNode.LeftNode;
if (currentNode.Value < parentNode.Value)
{
parentNode.LeftNode = currentNode.RightNode;
}
else if (currentNode.Value > parentNode.Value)
{
parentNode.RightNode = currentNode.RightNode;
}
}
}
else
{
var leftmost = currentNode.RightNode.LeftNode;
var leftmostParent = currentNode.RightNode;
while (leftmost.LeftNode != null)
{
leftmostParent = leftmost;
leftmost = leftmost.LeftNode;
}
leftmostParent.LeftNode = leftmost.RightNode;
leftmost.LeftNode = currentNode.LeftNode;
leftmost.RightNode = currentNode.RightNode;
if (parentNode == null)
{
this.rootNode = leftmost;
}
else
{
if (currentNode.Value < parentNode.Value)
{
parentNode.LeftNode = leftmost;
}
else if (currentNode.Value > parentNode.Value)
{
parentNode.RightNode = leftmost;
}
}
}
}
}
}
public BinarySearchTree()
{
this.rootNode = null;
}
