Lecture 7 Objectives

At the end of today's class you should

KNOW:

That well-designed object-oriented programs rely on dynamic dispatch rather than on explicitly checking object types
Why an additional invariant is needed for the BST to ensure improved worst-case performance over a list for the hasElt operation
That an AVL tree is BST for which the heights of the two subtrees of any given node differ by at most 1

BE ABLE TO:

Explain the advantages of using dynamic dispatch over the use of instanceof
Rewrite a method that uses instanceof in a way that relies on dymamic dispatch instead
Identify trees as binary trees, binary search trees, AVL trees

Sample Exam Question:

In a short, well-written paragraph, explain why the worst-case performance for hasElt() when a set is implemented as a BST is no better than the worst-case performance for hasElt() when a set is implemented as a list.