/// <summary>
/// Constructs the tree
/// </summary>
public BinarySearchTree()
{
this.root = null;
}
private void Remove(BinaryTreeNode <T> node)
{
// Case 3: If the node has two children.
// Note that if we get here at the end
// the node will be with at most one child
if (node.LeftChild != null && node.RightChild != null)
{
BinaryTreeNode <T> replacement = node.RightChild;
while (replacement.LeftChild != null)
{
replacement = replacement.LeftChild;
}
node.Value = replacement.Value;
node = replacement;
}
// Case 1 and 2: If the node has at most one child
BinaryTreeNode <T> theChild = node.LeftChild != null ?
node.LeftChild : node.RightChild;
// If the element to be deleted has one child
if (theChild != null)
{
theChild.Parent = node.Parent;
// Handle the case when the element is the root
if (node.Parent == null)
{
root = theChild;
}
else
{
// Replace the element with its child subtree
if (node.Parent.LeftChild == node)
{
node.Parent.LeftChild = theChild;
}
else
{
node.Parent.RightChild = theChild;
}
}
}
else
{
// Handle the case when the element is the root
if (node.Parent == null)
{
root = null;
}
else
{
// Remove the element - it is a leaf
if (node.Parent.LeftChild == node)
{
node.Parent.LeftChild = null;
}
else
{
node.Parent.RightChild = null;
}
}
}
}