ALGORITHMS AND DATA STRUCTURES I PROGRAMMING ASSIGNMENT 3

CSC 225
ALGORITHMS AND DATA STRUCTURES I
PROGRAMMING ASSIGNMENT 3

1 Programming Assignment
The assignment is to implement a hash table for strings of characters which uses open addressing
and double hashing to resolve collisions. Two hash functions have been provided to use for double
hashing. The data structure used to represent the hash table must be an array.
Your implementation must be be able to insert an arbitrary number of strings into the hash
table as well as remove strings from the hash table. Furthermore, the load factor of your hash table
must remain in the range [0.25, 0.75] at all times. Therefore, when inserting or removing a string
that would move the load factor outside this range, the hash table will need to be resized. You may
use any resizing scheme you choose.
A Java template has been provided containing empty functions insert, find, remove, and
resize. Your task is to write the body of each of the functions. You must use the provided
Java template as the basis of your submission, and put your implementation inside the provided
functions in the template. You may not change the name, return type or parameters of any of the
provided functions. You may add additional functions and classes as needed. Since you are are
only permitted to submit one file, any extra classes must be contained in the HashTable.java file.
The main function in the template contains code to help you test your implementation by
entering test data or reading it from a file. You may modify the main function, but only the
contents of the provided functions (and any functions or classes you have added) will be marked,
since the main function will be deleted before marking begins. Please read through the comments
in the template file before starting.
2 Test Datasets
The dataset for this assignment will be a collection of place names (cities, towns, etc.). A set of
input files containing test data are available on conneX. You should ensure that your implementation behaves correctly on these test files before submitting. It may also be helpful to test your
implementation on a variety of other inputs, since the posted data may not cover all possible cases.
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3 Evaluation Criteria
The programming assignment will be marked out of 40, based on a combination of automated
testing (using test data similar to the ones posted on conneX) and human inspection.
Score Description
0 - 10 Submission does not compile or does not conform to the provided
template.
11 - 20 The implemented hash table is substantially inaccurate on the
tested inputs.
21 - 30 The implemented hash table is partially complete, with some of
the required functions not working correctly.
31 - 40 The implemented hash table is complete and implements each of
the required functions correctly.
To be properly tested, every submission must compile correctly as submitted, and must be based
on the provided template. If your submission does not compile for any reason (even trivial
mistakes like typos), or was not based on the template, it will receive at most 10 out
of 40. The best way to make sure your submission is correct is to download it from conneX after
submitting and test it. You are not permitted to revise your submission after the due date, and late
submissions will not be accepted, so you should ensure that you have submitted the correct version
of your code before the due date. conneX will allow you to change your submission before the due
date if you notice a mistake. After submitting your assignment, conneX will automatically send
you a confirmation email. If you do not receive such an email, your submission was not received.
If you have problems with the submission process, send an email to the instructor before the due
date.
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