複選題

17. Which of the following statements are true?
(A) An insertion in AVL tree requires Ω(logn) single- and double-rotations in the worst case.
(B) An insertion in AVL tree requires O(1) single- and double-rotations in the worst case.
(C) A deletion in AVL tree requires Ω(logn) single- and double-rotations in the worst case.
(D) A deletion in AVL tree requires O(1) single- and double-rotations in the worst case.
(E) There is no red left child in AA tree.