You can turn it in using the catalyst Drop-box linked on our course web page.
Be sure to read the turn-in info before you submit!
The purpose of this project is to implement a Stack ADT in the two most common ways, an array and a linked list. First, you'll implement stacks for Java double numbers. Then, you'll implement generic stacks and instantiate them with type Double.
Your Stack implementations will be used to do sound manipulation, namely reversing a sound clip. This process, called "backmasking," was used by musicians including the Beatles, Jimi Hendrix, and Ozzy Ozbourne, although it seems to have fallen out of favor in recent years. Click here for a history of this (sometimes controversial!) practice. "But wait," you say, "CSE 143 never taught me how to work with music..." Don't worry! All the music-handling parts have been done for you.
Even though the music-reversing code will use your stack implementations in only certain ways, you should test that your stacks are correct in all cases, not just those used by the reverse program.
You will write a program that reads a sound file in the .dat format (explained below), and writes another .dat sound file which is the reverse of the first. We provide you with a class Reverse whose main method reads in a .dat sound file, pushes all the sound values on a stack, then pops them all off and writes them into a new .dat sound file. We've also provided you interfaces DStack (for Phase A) and GStack (for Phase B), which define the stacks you will implement. Your first job is to familiarize yourself with these files.
To begin with, you need to provide two stack implementations, one using an array and one using a linked list. They should be called ArrayStack and ListStack, respectively. They should implement the DStack interface given to you. Once you provide these implementations, Reverse should work and create backwards sound files. It should take no more than a page or two of code to provide the implementations. Your array implementation should start with a small array (say, 10 elements) and resize to use an array twice as large whenever the array becomes full, copying over the elements in the smaller array. Both ArrayStack and ListStack should throw an EmptyStackException if pop() or peek() is called when the stack is empty. To use EmptyStackException, add the following line to your file:
import java.util.EmptyStackException;
Note that your solution to Phase A does not require making changes to Reverse.java.
For phase B, you need to provide two more stack implementations, these implementing the interface GStack<T>. Create classes called GArrayStack and GListStack that are just like ArrayStack and ListStack except that they are generic in the type of elements kept in the stack. The simplest approach is to copy ArrayStack and ListStack and then make appropriate changes. Normally such copy-and-paste is poor form, but here the pedagogical purpose is to show you how little you need to change to make the code generic — and we want to grade all four stack implementations.
To use your generic stacks you will need to make some additions to Reverse.java by replacing the 3 occurrences of:
System.err.println("no support for generics yet");
System.exit(1);
with appropriate code. Again, the code you write will be only slightly different from non-generic code that is already there. Do not make other changes to Reverse.java.
Note: Creating generic arrays can be a bit tricky at first; check out these notes (mainly workaround #1) for help.The Reverse program takes 4 arguments (a.k.a. "command-line arguments"). The first is the word array or list, and specifies which implementation to use. The second is the word double or generic; the latter is for Phase B. The next two are the input and output .dat file names (you need to include the .dat extension). From the command-line, you can run the program with something like:
java Reverse list double in.dat out.dat
To run your program in Eclipse, create a "Run Configuration" and under the "Arguments" tab put the arguments (e.g., list double in.dat out.dat) in the "Program arguments" box.
To test your program, you will need a .dat file, which you can create from a .wav file as explained in the Digital Sound section. It may also be useful for you to create some short .dat files by hand to aid testing.
Note that the write-up questions can all be turned in for Phase B, but some of them (1-7) refer to work you did in Phase A, so you may wish to start on them early.
Turn in a report answering the following questions
The following list of suggestions are meant for you to try if you finish the requirements early. Recall that any extra-credit points you earn for these are kept separate and will be used to adjust your grade at the end of the quarter, as detailed in the course grading policy. Note: please turn in all extra credit files separately, as described under 'Turn-in'.
Phase A:
Phase B:
Like many assignments, this has been passed down to us through the vaporous mists of time. Among all our fore-bearers, we would especially like to thank Ashish Sabharwal, Adrien Treuille, and Adrien's Data Structures professor, Timothy Snyder.