Solving Graph Problems
There are many situations when
you'll have to use your knowledge about graphs to solve real-life problems.
The problem described here is one people in certain businesses
(road-construction, communications, etc.) face all the time.
A complete description of the problem
is included in a memo from your instructor.
What you'll turn in
A write protected floppy disk (3.5") or a CD which contains:
- the source file(s) for your program. Note that grading,
as described below, considers both the functionality and the readability
of your code. The grading sheet is included for your reference.
You must follow the
coding style and documentation standards
used in the Computer Science Department.
- DOS executable named assign1. If you prefer to use UNIX instead, then you
shall turn in an executable made for Linux.
- README file indicating what the program does, how to build the executable,
the platform it's been tested on, and how to run it, plus any other information
you consider useful - like the name of the author, etc.
- two input files (use the extension .din for the name), you have used
to test your program (with a minimum of four vertices each)
- the corresponding output files (with the extension .out)
- a memo describing your work. You will indicate what you have looked
for and how you solved the problem. Direct the memo to your class instructor.
Attached to the memo will be a document that introduces the necessary theoretical background.
- the memo with the attached theoretical background
- a listing of the source code
- listings of the sample input files and the corresponding output.
A professional look of your work is expected. Loose items will be rejected.
A binder (or an envelope) to hold your work together is required.
For each business day you turn in your project earlier you receive a
5% bonus. However, penalties increase by 5% as well. You can turn in your
assignment up to ten business days ahead of the deadline.
- A mark between 0 and 10 for functionality. The mark basically indicates
in what measure your program works properly and how well you have followed
the initial specification.
- A mark between 0 and 10 for readability. This mark indicates how well
documented your program is; it also considers the general appearance of
your final report.
- Multiply the above two marks to get the mark for this programming assignment.
- You turn in your assignment three days earlier: a 3*5=15% bonus will
be added to your assignment mark
- We find a single mistake in the functionality section and the penalty
for that mistake is 0.5 points. Since you have turned the assignment three
days earlier than the deadline, the penalty becomes 0.5*(1+3*5%)=0.5*(1+3*0.05)=0.575
- We calculate the mark by multiplying the marks for the functionality
and readability; in your case the mark for functionality is 10-0.575=9.425,
and the mark for readability is 10. The result is 9.425*10=94.25
- We add the bonus to this mark: 94.25+94.25*15%=108.38 which we round
to 108. This is your final mark.
You may be asked to do a code review with your instructor.
||September 25, 2002
A computer business in Chicago -- they do networking -- has asked me
to find a solution to their problem.
I pass the problem on to you and I just add some details about input and
The problem can be modelled as a graph problem. What you
have to do is to write a general program that takes a description
of a connected graph from standard input, finds the shortest path between
two vertices specified in the command line,
and prints the result out to standard output.
Here is a description for the input and the output of your program.
Each line in the input
will give the names of two vertices in the graph and the weight of the edge
connecting them. For simplicity vertex names are non-negative integers.
Weights are non-negative integers as well.
There must be at least two vertices, the graph must be connected and each
edge may be listed only once. Your program must enforce these rules.
Here is an example of input for a graph with four vertices:
0 1 10
1 2 9
0 3 8
2 3 12
There are two output lines: the first contains the names of the
vertices in the shortest path, the second is the actual length of
the shortest path.
Using the graph described by the sample above, let's assume the
program is run as
assign1 0 2
Then the output will be:
Please note that if your program reads input from standard
input then it can get input from a file by using input redirection. Similarly,
if the program writes to standard output, then the output can be easily written
to a file by using output redirection.
For example, assign1 0 2 < test1.din
will get the graph description from the file named
(< indicates input redirection), and the output will be written to standard
output (typically the monitor).
On the other hand, if you do assign1 0 2 > myOutputFile.out
then the graph description will come from standard input (typically your keyboard) and the
output will be written to
(> indicates output redirection).
Finally, you can do both input and output redirection at the same time:
assign1 0 2 < test1.din > test1.out
$Id: assign1.html,v 1.1 2002/09/26 12:18:50 virgil Exp $