/// <summary> Internal method to get element field.</summary>
/// <param name="t">the node.
/// </param>
/// <returns> the element field or null if t is null.
/// </returns>
private Comparable elementAt(BinaryNode t)
{
return(t == null?null:t.element);
}
/// <summary> Double rotate binary tree node: first right child
/// with its left child; then node k1 with new right child.
/// For AVL trees, this is a double rotation for case 3.
/// </summary>
internal static BinaryNode doubleWithRightChild(BinaryNode k1)
{
k1.right = withLeftChild(k1.right);
return(withRightChild(k1));
}
internal BinaryNode(Comparable theElement, BinaryNode lt, BinaryNode rt)
{
element = theElement;
left = lt;
right = rt;
}
/// <summary> Double rotate binary tree node: first left child
/// with its right child; then node k3 with new left child.
/// For AVL trees, this is a double rotation for case 2.
/// </summary>
internal static BinaryNode doubleWithLeftChild(BinaryNode k3)
{
k3.left = withRightChild(k3.left);
return(withLeftChild(k3));
}