Description
Array List
You are to code an Array List. An Array List is a list data structure backed by an array.
Your array list implementation will implement the ArrayListInterface provided. A constructor
stub is provided. You must add any necessary statements to this constructor. Do not change the
constructor provided or implement a different one.
Adding
You will implement three add() methods. One will add to the front, one will add to the back, and one
will add anywhere in the list. See the interface for more details.
Removing
Removing, just like adding, can be done from the front, the back, or anywhere in your ArrayList. When
removing from the front or from the middle of the list, the element should be removed and all subsequent
elements should be shifted forward by one position. When removing from the back, the last element
should be set to null in the array. All unused positions in the backing array must be set to
null. See the interface for more details.
Capacity
The starting capacity of your ArrayList should be the constant INITIAL CAPACITY defined in ArrayListInterface.
Reference the constant as-is. Do not simply copy the value of the constant. If, while adding an element,
the ArrayList does not have enough space, you should regrow the backing array to twice its old capacity.
Do not regrow the backing array when removing elements.
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Homework 1: Array List Due: See T-Square
A note on JUnits
We have provided a very basic set of tests for your code, in ArrayListStudentTests.java. These
tests do not guarantee the correctness of your code (by any measure), nor does it guarantee you any
grade. You may additionally post your own set of tests for others to use on the Georgia Tech GitHub as
a gist. Do NOT post your tests on the public GitHub. There will be a link to the Georgia Tech GitHub
as well as a list of JUnits other students have posted on the class Piazza (when it comes up).
If you need help on running JUnits, there is a guide, available on T-Square under Resources, to help
you run JUnits on the command line or in IntelliJ.
Style and Formatting
It is important that your code is not only functional but is also written clearly and with good style. We
will be checking your code against a style checker that we are providing. It is located in T-Square, under
Resources, along with instructions on how to use it. We will take off a point for every style error that
occurs. If you feel like what you wrote is in accordance with good style but still sets off the style checker
please email Carey MacDonald (careyjmac@gatech.edu) with the subject header of “CheckStyle XML”.
Javadocs
Javadoc any helper methods you create in a style similar to the existing Javadocs. If a method is
overridden or implemented from a superclass or an interface, you may use @Override instead of writing
Javadocs. Any Javadocs you write must be useful and describe the contract, parameters, and return
value of the method; random or useless javadocs added only to appease Checkstyle will lose points.
Exceptions
When throwing exceptions, you must include a message by passing in a String as a parameter. The message must be useful and tell the user what went wrong. “Error”, “BAD THING HAPPENED”,
and “fail” are not good messages. The name of the exception itself is not a good message.
For example:
throw new PDFReadException(“Did not read PDF, will lose points.”);
throw new IllegalArgumentException(“Cannot insert null data into data structure.”);
Generics
If available, use the generic type of the class; do not use the raw type of the class. For example, use new
ArrayList() instead of new ArrayList(). Using the raw type of the class will result in a
penalty.
Forbidden Statements
You may not use these in your code at any time in CS 1332.
• break may only be used in switch-case statements
• continue
• package
• System.arraycopy()
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Homework 1: Array List Due: See T-Square
• clone()
• assert()
• Arrays class
• Array class
• Collections class
• Collection.toArray()
• Reflection APIs
• Inner or nested classes
Debug print statements are fine, but nothing should be printed when we run your code. We expect
clean runs – printing to the console when we’re grading will result in a penalty. If you submit these, we
will take off points.
Provided
The following file(s) have been provided to you. There are several, but you will only edit one of them.
1. ArrayListInterface.java
This is the interface you will implement. All instructions for what the methods should do are in
the javadocs. Do not alter this file.
2. ArrayList.java
This is the class in which you will implement the interface. Feel free to add private helper methods
but do not add any new public methods, inner/nested classes, instance variables, or
static variables.
3. ArrayListStudentTests.java
This is the test class that contains a set of tests covering the basic operations on the ArrayList
class. It is not intended to be exhaustive and does not guarantee any type of grade. Write your
own tests to ensure you cover all edge cases.
Deliverables
You must submit all of the following file(s). Please make sure the filename matches the filename(s)
below. Be sure you receive the confirmation email from T-Square, and then download your uploaded
files to a new folder, copy over the interfaces, recompile, and run. It is your responsibility to re-test your
submission and discover editing oddities, upload issues, etc.
1. ArrayList.java
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