CSE 373: Data Structures and Algorithms, Winter 2013

Homework 6 (The Rotating Dead) FAQ

Q: What are some good resources or examples I can look at to get started on this program?

A: Look at the lecture slides and the TreeSet example from Friday's lecture. If you want to read more about implementing AVL trees, see Chapter 4 of the Weiss textbook.

Q: Does my HvZPlayer class still need to have an equals and hashCode method from HW4?

A: The hashCode method will probably not be used. But equals is still important, and in general, when you override equals, you should override hashCode. You won't be graded on methods outside of compareTo, but we recommend that you leave in the methods you wrote in HW4.

Q: What is a protected method? Why are the methods I need to write in this assignment declared as protected? Shouldn't they be public so that the client can call them? Should I declare all of my fields as protected? ...

A: A protected field can be seen by the class in which it is declared, along with any subclasses and classes in the same package. The methods in this assignment are protected because the abstract superclass has already written the public methods and you don't need to write those. You are overriding the protected helper methods that the client is using to recursively implement the adding and removing operations on the tree. The client will call the abstract class's public method, which will then call your protected method as a helper. In terms of fields, no, you should not declare your fields as protected on this assignment. Fields should almost always be private except in rare cases.