COSC 504: Efficient Computing Methods

Project 5
Fall 2007

Due: Dec 7 @ 5 PM
10 points

Implement one of the algorithms from lecture for finding the shortest path. The input should consist of the number of vertices, their labels, and their weights followed by pairs of vertices. The program should read a filename from the command line and process the file to create the graph and find the shortest paths between each pair of vertices. The program should output for each pair the path's length and vertices. As an example, input for the graph

might correspond to 

5
A B C D E
0 3 5 0 0
3 0 9 0 0
5 9 0 0 3
0 0 0 0 1
0 0 3 1 0
A C
D B
In this case, the program should output: 
path = A, C; cost = 5
path = D, E, C, A, B; cost = 12
Your program must work for any simple weighted graph, such as this graph representing roads in France:

For your convenience, I put the file france.dta in my top-level directory on seva, which you can copy with the command 

cp ~maloofm/france.dta ./
This will copy the file into your current directory.

Implementing a shortest-path algorithm will probably require some containers other than the graph. You can use STL containers or containers you've implemented for previous projects.

Bonne chance!

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 5
// 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 p5. To create this subdirectory, type 

seva% mkdir p5
To descend into the directory, type 
seva% cd p5
All of the files for your project should be in this directory. The submit program should be above this directory: 
seva% ls ..
p5/ 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 p5 directory, type 

seva% cd ..
You should be above the p5 directory: 
seva% ls
p5/ 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 p5 by typing 

seva% mv p5 maloofm
Create a zip file of the directory and its contents by typing 
seva% zip -r p5.zip maloofm/*
This command creates a zip file named p5.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 p5 -f p5.zip
p5 is the name of the assignment (-a) and p5.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 p5
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 p5.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 p5.zip, type at the seva prompt 

seva% uuencode p5.zip p5.zip | mail cosc173@cush.georgetown.edu
Briefly, uuencode encodes the binary file p5.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.