private Node <T> Remove(T value, Node <T> at)
{
if (at == null)
{
return(null);
}
int comparison = value.CompareTo(at.Value);
if (comparison < 0)
{
at.Left = Remove(value, at.Left);
}
else if (comparison > 0)
{
at.Right = Remove(value, at.Right);
}
else //comparison == 0
{
if (at.Left == null)
{
return(at.Right);
}
if (at.Right == null)
{
return(at.Left);
}
//both children exist
RemoveMin(at.Right, ref at.Value);
}
return(Node <T> .Balance(at));
}
private static Node <T> RemoveMin(Node <T> at, ref T minValue)
{
if (at.Left == null)
{
minValue = at.Value;
return(at.Right);
}
at.Left = RemoveMin(at.Left, ref minValue);
return(Node <T> .Balance(at));
}
private static Node <T> Add(T item, Node <T> at)
{
if (at == null)
{
return new Node <T> {
Value = item
}
}
;
if (item.CompareTo(at.Value) <= 0)
{
at.Left = Add(item, at.Left);
}
else
{
at.Right = Add(item, at.Right);
}
return(Node <T> .Balance(at));
}
