public void Clear()
{
_root = null;
}
public bool Remove(TK key)
{
BinaryTreeNode <TK, TV> parent = null;
var current = _root;
while (current != null)
{
var compareTo = key.CompareTo(current.Key);
if (compareTo == 0)
{
if (current.Lower == null && current.Higher == null)
{
if (parent == null)
{
_root = null;
return(true);
}
if (parent.Higher == current)
{
parent.Higher = null;
}
else
{
parent.Lower = null;
}
return(true);
}
if (current.Lower == null || current.Higher == null)
{
var child = current.Lower ?? current.Higher;
if (parent == null)
{
_root = child;
return(true);
}
if (parent.Higher == current)
{
parent.Higher = child;
}
else
{
parent.Lower = child;
}
return(true);
}
var rightSubtree = current.Higher;
var currentLowestParent = current;
var currentLowest = rightSubtree;
while (currentLowest.Lower != null)
{
currentLowestParent = currentLowest;
currentLowest = currentLowest.Lower;
}
current.Key = currentLowest.Key;
current.Value = currentLowest.Value;
currentLowestParent.Lower = null;
return(true);
}
parent = current;
current = compareTo < 0 ? current.Lower : current.Higher;
}
return(false);
}