CS 3100 Proramming Assignment #2 - Computer Science

CS 3100 Programming Assignment #2
Comparing Sort Algorithms
Finished Program DUE Wednesday, October 17 -- you will not turn in a preliminary version of this program.
Write a program that REPEATEDLY
1. prompts the user to enter a filename.
2. opens the file
3. reads a comment from the first line
4. reads an integer N from the second line (e.g. N = 1000)
5. reads N integers from the rest of the file, putting them into
consecutive locations in an array.
6. sorts an identical copy of the array using each of the following
methods:
a. selection sort
b. insertion sort
c. quick sort
d. heap sort
7. writes the name of the input file
8. writes the comment from the input file
9. writes a report of the number of comparisons done in each sort,
and the number of swaps done in each sort.
10. asks the user if he/she wishes to continue
UNTIL the user wishes NOT to continue.
MOTIVATION:
Working on this program and actually experiencing the differences in
runtime is a nice way to get familiar with analysis of algorithms. This
is an important part of the "science" in computer science.
DETAILS:
You need to arrange to pass in a NEW COPY of your original array to
each sorting function, because otherwise the first function will be the
only one that sorts the original list, and the others will just be resorting
a list that is already in order.
When you count "swaps", count the number of calls to the procedure
Swap. (You will be using code I give to you, and that code uses
procedure Swap to do all the data moves.)
When counting comparisons, count ONLY comparisons of the array
contents (the things that are being sorted), not the array indices.
The file sorts2.cpp contain all the sort code you need for this
program. If you wish, you can do this assignment just by adding code
to sorts2.cpp.
Data files are on the class web site:
http://www.cs.csustan.edu/~lamie/cs3100/main.htm
SAMPLE INPUT and OUTPUT files
The examples below should be enough to allow you to figure out what
you need to make your program do. Don't believe the counts in the
sample output files. They are just made-up numbers that I thought
seemed plausible.
CS 3100 Programming Assignment #2 Page 1 of 2

------------------- sample inputs -----------------
Here is a sample input file we will call ran1000:
This is a random list of 1000 numbers.
1000
233 871 954 23 1245 (... the file continues ... 1000
numbers in all, starting with 233)
Here is a sample file we will call ord50:
This is an ordered list of 50 numbers.
50
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
23 24
25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43
44 45
46 47 48 49 50
------------------- sample output -----------------
File Name: ran1000
File comment:
This is a random list of 1000 numbers.
Here are the results of the sorts:
compares
swaps
selection sort 499500 1000
insertion sort 251000 250000
quick sort 12000 6500
heap sort 12450 7453
File Name: ord50
File comment:
This is an ordered list of 50 numbers.
compares
swaps
selection sort 1225 50
insertion sort 49 0
quick sort 1250 680
heap sort 290 153
TESTING:
Be sure to test your program on large lists (up to 1000 elements or
more), medium size lists, small lists, ordered lists (both ascending and
descending order) and unordered lists. Test all possible combinations
of these list characteristics. This is a very important aspect. It will
determine what you learn from this assignment, and will also
determine a large fraction of your grade.
In the header of your program, include a paragraph or two describing
what you learned from writing and testing this program. Do your very
best to make this well-written. This will be another aspect of the
assignment that will count heavily.
WHAT TO TURN IN:
Turn in the source code, plus a script that shows the full range of the
testing you did. For this program *do not* cat the input files when you
make the script of the tests! Most of the input files will be way too
long for this to be practical. If you write the program according to the
specifications I gave you, and if the comments you put in the input
files are intelligible, then the information printed by the program will
tell me what I need to know about the input files.
Turn in the program source code and the script by email before
midnight Wednesday, October 17.
CS 3100 Programming Assignment #2 Page 2 of 2