Assignment #3 C Programming

COMPSCI 2211b
Software Tools and Systems Programming
Assignment #3
C Programming

Total: 100 Points (5% of Final Grade)
CS2211 - Software Tools and Systems Programming Assignment #3
Learning Outcomes
By completing this assignment, you will gain and demonstrate skills relating to:
ˆ Writing, compiling and running C programs.
ˆ Use of input/output functions (printf & scanf)
ˆ Practice with loops, conditional statements and functions.
ˆ Documenting and commenting C source code.
Instructions
For this assignment, an electronic submission is required through OWL. This submission should
include the source code for each of the C programs your are required to create. These files should
be named as per the instructions given in each question and end in a .c file extension. The files
should be attached individually, and not contained in an archive (e.g. zip, tar, etc.) or other binary
format (e.g. they should not be in a word or PDF document). You can copy your files off the course
server using the scp command on the lab computers or using a UNIX-Like operation system. On
Windows you can use a program like WinSCP to copy files to/from the course server.
All C programs must work on the course server. Programs will be marked on the course
sever and it is expected that students at least test their code on the server before submitting. It
will be assumed that the GNU89 C standard (the default for gcc on the course server) is being used
unless you specifically state otherwise in a comment on the first line of your C source code. Your
code must work with the GCC compiler on the course server and you may only use C standards
that are supported by this compiler. C++ code or code written in other programming languages
will be given 0 marks.
You must document your code. It is expected that you document your C source code with
comments. Each program should have comments at the top of the file that state what C standard
you are using (if different from the default), any special instructions for compiling/running your
code, your name, student number and a short description of what the program does. You are
also expected to include in-line comments throughout your code to make each line understandable
by anyone who reads it. Lines that are self explanatory or straightforward do not need to be
documented.
You will be assessed on the following:
ˆ Completion of each question correctly.
ˆ Providing your source code as required in the above instructions.
ˆ Documenting your code with comments as required in the above instructions.
ˆ Ensuring that your code works on the course server.
ˆ Naming your files correctly and submitting via OWL.
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CS2211 - Software Tools and Systems Programming Assignment #3
Questions
Question 1 (23 Marks)
Create a C program named phone.c that takes as input (over standard input) a 10 digit phone
number and a single character. The format of the phone number will be DDDDDDDDDD, that is, 10
digits in a row with no spaces or other characters. The character will be a single uppercase or
lowercase letter between A and D (e.g. A, b, c, D, d, etc).
Your program will display a menu of options and ask the user for input as shown in the Example
Input/Output below (at the end of this question) and format the number based on the menu option
(character) input by the user. The following table describes how to format the phone number for
each menu option:
Menu Option Phone Number Format
A or a Local format: DDD-DDDD omit the area code (first 3 numbers). For
example, 5199145555 would become 914-5555.
B or b Domestic: (DDD) DDD-DDDD For example, 5199145555 would become
(519) 914-5555.
C or c International: +1-DDD-DDD-DDDD assume country code is 1. For
example, 5199145555 would become +1-519-914-5555.
D or d Odd: 0DDD 0DDD DDDD, use the minimum with specifier to output
each part of the phone number with at least 6 spaces and use the
precision specifier to output each number with at least 4 digits. Do
not pad the numbers manually (allow the specifier and printf to do this
for you). For example, 5199145555 would become ••0519••0914••5555
(spaces added by the minimum width specifier shown as •, red numbers
added by precision specifier).
Any other character Print an error message and exit with an exit status that indicates
failure.
You are required to do error checking to test for invalid input. You must check the return of scanf
and print an error if it aborted early. You must also check that no part of the input number is
negative and that the input option is valid. If an error is encountered print an error message and
exit with a non-zero exit status (to denote failure), otherwise exit with an exit status of 0 (to denote
success).
Hint: You do not need to use strings, arrays, pointers or loops for this question. If you are, you
are likely over thinking it.
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CS2211 - Software Tools and Systems Programming Assignment #3
Example Input/Output (input in green):
Example 1:
Input Phone Number: 5551234567
Format Options:
A) Local
B) Domestic
C) International
D) Odd
Input Option: A
Phone Number: 123-4567
Example 2:
Input Phone Number: 5551234567
Format Options:
A) Local
B) Domestic
C) International
D) Odd
Input Option: B
Phone Number: (555) 123-4567
Example 3:
Input Phone Number: 5551234567
Format Options:
A) Local
B) Domestic
C) International
D) Odd
Input Option: C
Phone Number: +1-555-123-4567
Example 4:
Input Phone Number: 5551234567
Format Options:
A) Local
B) Domestic
C) International
D) Odd
Input Option: D
Phone Number: 0555 0123 4567
Example 5:
Input Phone Number: 5551234567
Format Options:
A) Local
B) Domestic
C) International
D) Odd
Input Option: F
Error: Invalid Option!
Example 6:
Input Phone Number: Not a number
Error: Invalid Phone Number!
Example 7:
Input Phone Number: 1 2 3
Error: Invalid Phone Number!
Example 8:
Input Phone Number: 1234567
Error: Invalid Phone Number!
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CS2211 - Software Tools and Systems Programming Assignment #3
Question 2 (23 Marks)
Write a C program named dates.c that determines which of the entered dates comes later on the
calendar. The user may enter any number of dates. The user will enter 0/0/0 to indicate that no
more dates will be entered.
Dates will be entered in the mm/dd/yy format where mm is a two digit month number (1 to 12), dd
is a two digit day of the month (1 to 31) and yy is a two digit year (00 to 99). You should print an
error if an invalid date is entered (does not follow the format or out of the given ranges) and ask
the user for a new date (do not exit).
The user is allowed to input a one digit number (they do not need to pad it with a zero). For
example 3/6/8, 3/6/08, 3/6/18, 3/16/18, and 03/06/08 are all valid dates. When outputting,
the latest date, you should always pad the day, month and year to ensure they are two digits. For
example, 3/6/8 should be output as 03/06/08.
You do not have to check that the number of days are correct for a given month. For example,
you can consider 2/31/18 to be a valid date (February has 28 days). However, the number of days
must be in the range 1 to 31. The same date maybe input multiple times.
If the user does not input any dates before entering 0/0/0 an error should be displayed and the
program should exit with a non-zero exit status. Otherwise the exit status should be zero.
Hint: You do not need to use strings or arrays for this, nor do you need to store every date.
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CS2211 - Software Tools and Systems Programming Assignment #3
Example Input/Output (input in green):
Example 1:
Enter a date (mm/dd/yy): 3/6/08
Enter a date (mm/dd/yy): 5/17/07
Enter a date (mm/dd/yy): 6/3/07
Enter a date (mm/dd/yy): 0/0/0
03/06/08 is the latest date
Example 2:
Enter a date (mm/dd/yy): 10/2/18
Enter a date (mm/dd/yy): 0/0/0
10/02/18 is the latest date
Example 3:
Enter a date (mm/dd/yy): 1/1/1
Enter a date (mm/dd/yy): 12/31/99
Enter a date (mm/dd/yy): 05/05/05
Enter a date (mm/dd/yy): 5/5/5
Enter a date (mm/dd/yy): 12/31/99
Enter a date (mm/dd/yy): 9/15/15
Enter a date (mm/dd/yy): 0/0/0
12/31/99 is the latest date
Example 4:
Enter a date (mm/dd/yy): 0/0/0
Error: At least one date must be input!
Example 5:
Enter a date (mm/dd/yy): 7/0/8
Error: Invalid day number!
Enter a date (mm/dd/yy): 0/7/8
Error: Invalid month number!
Enter a date (mm/dd/yy): 7/7/-8
Error: Invalid year number!
Enter a date (mm/dd/yy): 13/7/8
Error: Invalid month number!
Enter a date (mm/dd/yy): 7/32/8
Error: Invalid day number!
Enter a date (mm/dd/yy): 7/7/100
Error: Invalid year number!
Enter a date (mm/dd/yy): 1/1/18
Enter a date (mm/dd/yy): 03/1/19
Enter a date (mm/dd/yy): 0/0/0
03/01/19 is the latest date
Example 5:
Enter a date (mm/dd/yy): -10/7/17
Error: Invalid month number!
Enter a date (mm/dd/yy): 10/-7/17
Error: Invalid day number!
Enter a date (mm/dd/yy): 0/0/0
Error: At least one date must be input!
Example 6:
Enter a date (mm/dd/yy): potato
Error: Invalid date format!
Enter a date (mm/dd/yy): 10/10/pizza
Error: Invalid date format!
Enter a date (mm/dd/yy): 10/$7/9
Error: Invalid date format!
Enter a date (mm/dd/yy): 10\7\9
Error: Invalid date format!
Enter a date (mm/dd/yy): 2/31/18
Enter a date (mm/dd/yy): 4/31/17
Enter a date (mm/dd/yy): 0/0/0
02/31/18 is the latest date
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CS2211 - Software Tools and Systems Programming Assignment #3
Question 3 (31 Marks)
The area of a circle of radius r is given by:
Area of a circle = π × r
2
Imagine that you divided this circle exactly into 4 quadrants. The area of one quadrant is then
0.25 × π × r
2
.
Let us set the radius of this circle to be r = 1. The equation hence becomes:
Area of one quadrant of a circle of radius 1 = 0.25 × π
We can simply say that:
π = 4 × the area of one quadrant of a circle of radius 1
To calculate the area of the shaded quadrant of this circle, you can use a random number generator
and guess effectively the correct value of the constant π.
The steps of this technique are as follows:
1. Generate a random real number between 0 and 1 and assign it to x.
2. Generate a random real number between 0 and 1 and assign it to y.
3. If x
2 + y
2 ≤ 1, it means that this (x, y) coordinate lies inside the shaded quadrant.
4. Repeat these steps N times, where N is sufficiently large number.
5. Calculate the ratio of the points located inside the circle to the total number of generated
points, i.e., N. This ratio should represent the ratio between the area of one quadrant of this
circle to the area of 1 × 1 square. That is, this ratio approximates the area of one quadrant
of this circle.
6. Multiply the calculated ratio by 4 to find an approximation of the mathematical constant π.
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CS2211 - Software Tools and Systems Programming Assignment #3
Use the above procedure to create a C program named pi.c to approximate the mathematical
constant π. This program should contain a function named estimate pi with the following function
prototype:
double estimate pi(long long n);
This function should take the value of N and return an estimation of pi using the technique
described in this question.
Your program must read (from standard input) and validate the value of N (a positive whole
number) from the user at the beginning of execution. You should print an error and exit with a
non-zero exit status if your program fails to read in or validate the value of N, otherwise exit with
an exit status of zero.
Write a loop inside your program to recalculate the value of π 10 times using your estimate pi
function and the given value of N from the user. Print each estimated value of pi with 10 digits of
precession and calculate the mean (the average value) and the standard deviation for results. Also
print the mean and standard deviation with 10 digits of precession.
mean =
Pi=n
i=1 xi
n
standard deviation =
sPi=n
i=1 x
2
i
n
− mean2
Test your program and ensure it works correctly for the following values of N (you do not need to
provide this output with your submission):
N = 10, N = 100, N = 1,000, N = 100,000, N = 10,000,000
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CS2211 - Software Tools and Systems Programming Assignment #3
Question 4 (23 Marks)
Write a C program named change.c that determines the smallest number of $20, $10, $5, $2, and
$1 bills/coins necessary to pay a dollar amount. The function prototype must be as follow:
void pay amount(int dollars, int *twenties, int *tens, int *fives, int *toonies,
int *lonnies);
where the dollar amount is represented by the dollars parameter. The twenties parameter points
to a variable in which the function will store the number of $20 bills required. The tens, fives,
toonies and lonnies parameters are similar.
To test your function, write a main function that asks the user to enter a positive integer value (to
be validated by your program). Consider this value to be the dollar amount (dollars) and get the
smallest number of bills/coins necessary to pay this amount, and then display the values returned
by the function.
If invalid input is entered (not a number or negative) you program should exit with an error message
and non-zero exit status, otherwise return an exit status of zero.
Test your code and ensure it works correctly with the following values (you do not need to provide
this output with your submission): 118, 81, 12, and 1.
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