public TreeNode Remove()
{
if (Left == null && Right == null)
{
if (Parent == null)
{
return(null);
}
if (Parent.Left == this)
{
Parent.Left = null;
}
else
{
Parent.Right = null;
}
Parent.UpdateHeight();
return(Parent.BalanceTree());
}
if ((Left == null) ^ (Right == null))
{
if (Left != null)
{
if (Parent != null)
{
if (Parent.Left == this)
{
Parent.Left = Left;
}
else
{
Parent.Right = Left;
}
Parent.UpdateHeight();
}
Left.Parent = Parent;
return(Left.BalanceTree());
}
if (Parent != null)
{
if (Parent.Left == this)
{
Parent.Left = Right;
}
else
{
Parent.Right = Right;
}
Parent.UpdateHeight();
}
Right.Parent = Parent;
return(Right.BalanceTree());
}
//Two child
if (Left != null && Right != null)
{
var prev = Previous();
prev.Remove();
Key = prev.Key;
}
return(BalanceTree());
}
