Practice: Separate chaining

This practice problem was originally no to be turned in, but I'm making it a homework problem to be turned in by Monday, Apr 20. The iterator part is still "optional", but I highly recommend that you test yourself to see if you can do it.

1. Introduction

The goal of this exercise is to understand separate chaining. It corresponds to Project 7.1 in the book, pg 525, with a couple of additions.

2. Set up

Find the project code for this at /homes/tvandrun/Public/cs345/hashing. This is the same code base as for the next two projects. The code contains packages adt, impl, and test.

3. Implementing separate chaining

Your task is to complete the following methods:

• find(), a helper method that, given a key, returns the pair (ie, node) containing that key, or null if none exists. (The solution is on pg 321).
• put(), to add a new association to the map, or overwrite an existing one. (The solution is on pg 322).
• remove(), which removes a key and its value from the map, if it exists. This corresponds to Project 7.1.a in the book.
• (For your own practice, not required for what you need to turn in)iterator(), which returns an iterator for the keys of this map. This is a difficult iterator. Recommended state variables for the iterator itself are a Pair variable referring to the node whose key will be returned by the next call to next() and an int variable referring to the bucket that pair is in. This corresponds to Project 7.1.b in the book.

To test everything except the iterator, use SCHMTestNoIterator. To test the whole thing, use SCHMTest

Turn in SeparateChainingHashMap.java to

/cslab/class/cs345/(your userid)/sepchain

Due Monday, Apr 16, 5:00pm

A solution will be available in /homes/tvandrun/Public/cs345/sepchain-soln.