public bool Remove(IAvlNode node)
{
if (node == null)
{
throw new ArgumentNullException(nameof(node));
}
var left = node.Left;
var right = node.Right;
var parent = node.Parent;
if (left == null)
{
if (right == null)
{
if (node == Root)
{
Clear();
return(true);
}
if (parent == null)
{
throw new Exception();
}
if (parent.Left == node)
{
parent.Left = null;
DeleteBalanceTree(parent, 1);
}
else
{
parent.Right = null;
DeleteBalanceTree(parent, -1);
}
}
else
{
if (node == Root)
{
node.Right.Parent = null;
Root = (T)node.Right;
return(true);
}
node.Right.Parent = node.Parent;
if (parent.Left == node)
{
parent.Left = node.Right;
DeleteBalanceTree(parent, 1);
}
else
{
parent.Right = node.Right;
DeleteBalanceTree(parent, -1);
}
}
}
else if (right == null)
{
if (node == Root)
{
node.Left.Parent = null;
Root = (T)node.Left;
return(true);
}
node.Left.Parent = node.Parent;
if (parent.Left == node)
{
parent.Left = node.Left;
DeleteBalanceTree(parent, 1);
}
else
{
parent.Right = node.Left;
DeleteBalanceTree(parent, -1);
}
}
else
{ // no (half-)leaf
IAvlNode successor;
if (node.Balance > -1)
{
successor = node.AvlGetNextNode();
}
else
{
successor = node.AvlGetPrevNode();
}
SwitchNodes(node, successor);
successor.UpdateAugmentedData();
return(Remove(node));
}
if (parent != null)
{
parent.UpdateAugmentedData();
}
Count--;
OnNodeRemoved(new TreeNodeEventArgs((T)node));
return(true);
}
