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Assignment 3 C Programming Solution
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 ( rst 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 speci er to output
each part of the phone number with at least 6 spaces and use the
precision speci er to output each number with at least 4 digits. Do
not pad the numbers manually (allow the speci er and printf to do this
for you). For example, 5199145555 would become 0519 0914 5555
(spaces added by the minimum width speci er shown as , red numbers
added by precision speci er).
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.
Example Input/Output (input in green):
Example 1:
Example 4:
Input Phone Number:
5551234567
Input Phone Number:
5551234567
Format Options:
Format Options:
A) Local
A) Local
B) Domestic
B) Domestic
C) International
C) International
D) Odd
D) Odd
Input Option:
A
Input Option:
D
Phone Number:
123-4567
Phone Number:
0555 0123 4567
Example 2:
Example 5:
Input Phone Number:
5551234567
Input Phone Number:
5551234567
Format Options:
Format Options:
A) Local
A) Local
B) Domestic
B) Domestic
C) International
C) International
D) Odd
D) Odd
Input Option:
B
Input Option:
F
Phone Number:
(555) 123-4567
Error:
Invalid Option!
Example 3:
Example 6:
Input Phone Number:
5551234567
Input Phone Number:
Not a number
Format Options:
Error:
Invalid Phone Number!
A) Local
B) Domestic
Example 7:
C) International
D) Odd
Input Phone Number:
1 2 3
Input Option:
C
Error:
Invalid Phone Number!
Phone Number:
+1-555-123-4567
Example 8:
Input Phone Number:
1234567
Error:
Invalid Phone Number!
3 o
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.
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): 10n7n9
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
Question 3 (31 Marks)
The area of a circle of radius r is given by:
Area of a circle = r2
Imagine that you divided this circle exactly into 4 quadrants. The area of one quadrant is then 0:25 r2.
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
We can simply say that:
= 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 e ectively the correct value of the constant .
The steps of this technique are as follows:
Generate a random real number between 0 and 1 and assign it to x.
Generate a random real number between 0 and 1 and assign it to y.
If x2 + y2 1, it means that this (x; y) coordinate lies inside the shaded quadrant.
Repeat these steps N times, where N is su ciently large number.
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.
Multiply the calculated ratio by 4 to nd an approximation of the mathematical constant .
Use the above procedure to create a C program named pi.c to approximate the mathematical constant . 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 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.
i=1 xi
standard deviation = s
P
i=n 2
n
P
i=n
i=1 xi
mean2
mean =
n
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
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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