COSC 173: Project 4

COSC 173: Data Structures

Project 4
Fall 2007

Due: Nov 20 @ 5 PM
10 points

Implement Cormen et al.'s B-tree algorithms as the class BTree<T>. It must be a template class. The constructor must take t, the order of the B-tree, as a parameter. You can assume that you'll be storing only the key, which will be a char (i.e., T = char). You must implement a destructor and a copy constructor.

The main function should read a set of commands from the file with the name that is the first argument from the command line. The first object will be an int specifying the order of the B-tree, which will be followed by a sequence of—hopefully familiar—commands: (P)rint, (I)nsert, (R)emove, (F)ind, and (#) for comments. The last three commands take a key (i.e., a char) as an argument. The main function should read t, create a BTree<T> object of that order, and perform each operation on the B-tree. Examples of such commands follow:

3
#
# Sample input for an order 3 B-tree
#
I F
I S
F Q
I Q
I K
I C
F L
I L
I H
I T
P
R L
P
R Q
P

The Print command should print the B-tree in a pre-order fashion with each node's keys preceded by the string "Keys: ". The Find command should report that the key was either found or not found.

The previous input should produce output similar to the following:

Inserting F
Inserting S
Did not find Q
Inserting Q
Inserting K
Inserting C
Did not find L
Inserting L
Inserting H
Inserting T
Keys: K
Keys: C F H
Keys: L Q S T
Removing L
Keys: K
Keys: C F H
Keys: Q S T
Removing Q
Keys: K
Keys: C F H
Keys: S T

Instructions for Electronic Submission: At the top of the file main.cc (or the file containing the main function), place the following header comment, with the appropriate modifications:

//
// COSC 173 Project 4
// Name: <your name>
// ID: <GoCard ID>
// E-mail: <e-mail address>
// Instructor: Maloof
// TA: <TA's name>
//
// In accordance with the class policies and Georgetown's Honor Code,
// I certify that, with the exceptions of the class resources and those
// items noted below, I have neither given nor received any assistance
// on this project.
//

Although you may use any C++ compiler to develop your program, it must run on seva, under Unix, and must compile using GNU g++. You must also provide a working UNIX Makefile for your project.

If you haven't already, place all of your code in a subdirectory named p4. To create this subdirectory, type

seva% mkdir p4

To descend into the directory, type

seva% cd p4

All of the files for your project should be in this directory. The submit program should be above this directory:

seva% ls ..
p4/ submit.jar

If you need to include a message to the TA or me about your submission, then place the message in a file named README. Place the README file in the project's directory.

Before submitting, to reduce the size of the zip file, type 'make clean'.

To move up from the p4 directory, type

seva% cd ..

You should be above the p4 directory:

seva% ls
p4/ submit.jar

(Additional useful Unix commands)

When you're ready to submit, change the name of the directory to your netid. For example, if your netid is maloofm, then rename the directory p4 by typing

seva% mv p4 maloofm

Create a zip file of the directory and its contents by typing

seva% zip -r p4.zip maloofm/*

This command creates a zip file named p4.zip by recursively (-r) copying all of the files (*) from the directory maloofm/.

To submit the zip file type

seva% java -jar submit.jar -a p4 -f p4.zip

p4 is the name of the assignment (-a) and p4.zip is the file (-f) to be submitted for that assignment.

If the program submits the file successfully, you will receive a receipt by e-mail at the address <netid>@georgetown.edu.

Submit your project only once.

Once you've submitted your project, it is important to keep an electronic copy on a university machine (e.g., seva) that preserves the modification date and time. If we lose your project or the submission system breaks, then we will need to look at the modification date and time of your project to ensure that you submitted it before it was due.

You can also change the directory's name back to the original name. For example,

seva% mv maloofm p4

Note that changing the name of the directory does not change the dates of the files in the directory. You can also remove the zip file from your directory:

seva% rm p4.zip

The TA who will be grading your projects this semester is listed on the main page. You must submit your project before 5 PM on the due date.

Plan B

Submit is pretty reliable, but it is software. If you're running submit correctly and you see an error message labeled as SEVERE, then it's time to execute Plan B by using mail to submit your project.

To accomplish this, assuming the file you want to submit p4.zip, type at the seva prompt

seva% uuencode p4.zip p4.zip | mail cosc173@cush.georgetown.edu

Briefly, uuencode encodes the binary file p4.zip as an ASCII file that can be transmitted as mail. This form of the uuencode command pipes the ASCII-encoded file through standard input and into (|) the mail command.

When we receive you mail, we will save it to a file and use uudecode to translate the ASCII-encoded file back to the original binary file. Virtually all mail clients automatically encode binary files in this way.