protected override BinarySearchTreeNode <T> DoDeleteRecursive(T value, BinarySearchTreeNode <T> root, ref bool result)
{
if (root == null)
{
result = false;
return(root);
}
int comparisonResult = Compare(root.Value, value);
if (comparisonResult == 0)
{
if (root.IsFull)
{
BinarySearchTreeNode <T> .ExchangeValues(root, DoGetMaximum(root.Left));
root.SetLeft(DoDeleteRecursive(value, root.Left, ref result));
root = EnsureBalanced(root, x => GetHeight(x.Right.Left) > GetHeight(x.Right.Right), RotateRL, RotateRR);
}
else
{
root = root.Left ?? root.Right;
}
}
else if (comparisonResult < 0)
{
root.SetRight(DoDeleteRecursive(value, root.Right, ref result));
root = EnsureBalanced(root, x => GetHeight(x.Left.Left) > GetHeight(x.Left.Right), RotateLL, RotateLR);
}
else
{
root.SetLeft(DoDeleteRecursive(value, root.Left, ref result));
root = EnsureBalanced(root, x => GetHeight(x.Right.Left) > GetHeight(x.Right.Right), RotateRL, RotateRR);
}
if (root != null)
{
root.SetHeight(Math.Max(GetHeight(root.Left), GetHeight(root.Right)) + 1);
}
return(root);
}
static int GetAVLTreeHeight(BinarySearchTreeNode <T> root)
{
if (root == null)
{
return(-1);
}
int lHeight = GetAVLTreeHeight(root.Left);
if (lHeight == int.MinValue)
{
return(int.MinValue);
}
int rHeight = GetAVLTreeHeight(root.Right);
if (rHeight == int.MinValue)
{
return(int.MinValue);
}
if (Math.Abs(lHeight - rHeight) > 1)
{
return(int.MinValue);
}
return(Math.Max(lHeight, rHeight) + 1);
}
public AVLTree(BinarySearchTreeNode <T> root, IComparer <T> comparer)
: base(root, comparer)
{
}
public AVLTree(BinarySearchTreeNode <T> root)
: base(root)
{
}
internal static int GetHeight(BinarySearchTreeNode <T> node)
{
return(node != null ? node.Height : -1);
}
public BinarySearchTreeNode <T> Insert(BinarySearchTreeNode <T> node, Action <T, T> visitAction)
{
return((BinarySearchTreeNode <T>)DoInsert(node, visitAction));
}
public BinarySearchTreeNode <T> Insert(BinarySearchTreeNode <T> node)
{
return(Insert(node, null));
}
public ReadOnlyCollection <BinarySearchTreeNode <T> > GetAncestors(BinarySearchTreeNode <T> node)
{
var ancestorList = DoGetAncestors(node).OfType <BinarySearchTreeNode <T> >().ToList();
return(new ReadOnlyCollection <BinarySearchTreeNode <T> >(ancestorList));
}
public BinarySearchTreeNode <T> GetLeastCommonAncestor(BinarySearchTreeNode <T> x, BinarySearchTreeNode <T> y)
{
return((BinarySearchTreeNode <T>)DoGetLeastCommonAncestor(x, y));
}