/* Parent Parent
* |- |+
* B A
* -/ \ / \+
* A BL -> AL B
* / \- +/ \
* AL C C BR
*
* - marks connections that are dettached
* + marks connections that are created
*/
private AvlTreeNode <T> _rotateRight(AvlTreeNode <T> b)
{
AvlTreeNode <T> a = b.Left;
AvlTreeNode <T> parent = b.Parent; // may be null if B was root
AvlTreeNode <T> c = a.Right; // may be null
var direction = b.Direction;
Debug.Assert(a != null);
// a.Left remains so no need to change this
// b.Right remains so no need to change this
_dettachFromParent(b); // b from parent
_dettachFromParent(a); // a from b
_dettachFromParent(c); // c from a
_attachToParentEdge(c, b.EdgeLeft());
_attachToParentEdge(b, a.EdgeRight());
_attachToParentEdge(a, parent.EdgeTo(direction));
_recalc(b);
_recalc(a);
return(a);
}
public static AvlTreeEdge <T> EdgeSelf <T>(this AvlTreeNode <T> source)
{
return(source.EdgeTo(AvlTreeNodeDirection.None));
}
public static AvlTreeEdge <T> EdgeParent <T>(this AvlTreeNode <T> source)
{
return(source.EdgeTo(AvlTreeNodeDirection.Parent));
}
