Problem
1. How much slower, on average, is searching a random binary search tree than is searching a completely balanced binary search tree?
2. What is the purpose of AVL trees?
3. What condition defines an AVL tree among all binary search trees?
4. Suppose that A is a base class and B is a derived class, and that we declare: A *pA; B *pB; Can pA reference an object of class B? Can pB reference an object of class A?