UMBC CMSC 104

CMSC104, Spring 2009
Programming Project 3
Math Helper v0.1

Out: Monday, April 27, 2009
Due Date: Monday, May 11, 2009 before 11:59pm

The Objective

This project is designed to give you practice with loops (for/while), switch statements and characters, as well as functions.

The Task

The local elementary school has asked you to volunteer as a helper in several of its classrooms. You have come to realize that the students need the most help with math (go figure!) There are few problems that you find yourself helping with frequently, so you have decided to create some software that will assist you. Your software is going to allow the user to print a multiplication table, find the greatest common divisor of two numbers and raise a number to a particular power.

The Details

For this project, since it is your first using functions, I am providing you with the function prototypes needed. You must use the following function prototypes EXACTLY. You may not change them in any way. However, you may use additional functions if you wish.

void PrintGreeting(void); - This function prints an explanation of the program to the user. You should assume the user knows nothing about the program and give a detailed explanation.
void PrintMenu(void); - This function should print a menu to the screen.
void PrintMultiplicationTable(int max); - This function should print a multiplication table to the screen. It takes the maximum multiplier/multiplicand needed to print the table. For example, if the max passed in is 3, your table should go from 1 to 3.
```
       1   2   3 
    ------------
 1 |   1   2   3 
 2 |   2   4   6 
 3 |   3   6   9 
	
```
Your table should be formatted nicely and contain the appropriate number of dashes to make up the table heading. You should also print the numbers as the column headings and at the beginning of each row. Hint: See if you can just get the basic table printed initially without the headings and numbers for the rows. Once you have that working, then work on the formatting.
int GreatestCommonDivisor(int num1, int num2); - This function should find the greatest common divisor. You can feel free to use the pseudocode from the "Algorithms I" lecture to find the greatest common divisor.
int RaiseToPower(int base, int power); - This function should raise a number to a power. It takes as arguments the base and the power you should raise it to. You MAY NOT use any functions from the math library to calculate the answer. You will receive no credit if you do so.
int GetPositiveInt(void); - This function reads a number in from the user and checks to make sure the number is greater than 0. If not, it continues to prompt the user until a number greater than 0 is entered. It returns the positive integer.

Your software should initially present a menu to the user. The menu should have four options. Each option will perform a different task. The options are as follows:

The 'M' option will print a multiplication table. You should ask the user for the maximum multiplier/multiplicand they would like to see in the table. Since we are only printing a table the multiplier and the multiplicand are the same number.
The 'G' option should find the greatest common divisor. You should ask the user for the numbers for which he/she would like to find the greatest common divisor.
The 'R' option will raise a number to a power. You should ask the user for the base number, as well as the power you should raise it to.
There should also be a Quit option on the menu. The menu should continue to display until the users enters a 'Q' (or 'q') for quit. If the user selects an incorrect menu option, you should print an appropriate error message and present the menu again.

Additional Information

You should make use of GetPositiveInt() to read in any integer input from the user.
You should allow the user to enter both upper and lowercase menu options.

Sample Output

linux3[92]% gcc -ansi -Wall proj3.c
linux3[93]% ls
a.out  proj3.c
linux3[94]% a.out

Welcome to Math Helper v0.1!

Your greeting goes here. It should contain a very
detailed explantion of the program.

M - Print a Multiplication Table
G - Find the Greatest Common Divisor
R - Raise a Number to a Power
Q - Quit

Enter your menu selection: M

Enter the maximum multiplier/multiplicand you would
like to see in the multiplication table: 8


Multiplication Table with a maximum multiplier/multiplicand of 8:

       1   2   3   4   5   6   7   8
    --------------------------------
 1 |   1   2   3   4   5   6   7   8
 2 |   2   4   6   8  10  12  14  16
 3 |   3   6   9  12  15  18  21  24
 4 |   4   8  12  16  20  24  28  32
 5 |   5  10  15  20  25  30  35  40
 6 |   6  12  18  24  30  36  42  48
 7 |   7  14  21  28  35  42  49  56
 8 |   8  16  24  32  40  48  56  64


M - Print a Multiplication Table
G - Find the Greatest Common Divisor
R - Raise a Number to a Power
Q - Quit

Enter your menu selection: m

Enter the maximum multiplier/multiplicand you would
like to see in the multiplication table: 4


Multiplication Table with a maximum multiplier/multiplicand of 4:

       1   2   3   4
    ----------------
 1 |   1   2   3   4
 2 |   2   4   6   8
 3 |   3   6   9  12
 4 |   4   8  12  16


M - Print a Multiplication Table
G - Find the Greatest Common Divisor
R - Raise a Number to a Power
Q - Quit

Enter your menu selection: G

Enter the first integer: 35
Enter the second integer: 20

The greatest common divisor of 35 and 20 is 5.

M - Print a Multiplication Table
G - Find the Greatest Common Divisor
R - Raise a Number to a Power
Q - Quit

Enter your menu selection: G

Enter the first integer: 31
Enter the second integer: 19

The greatest common divisor of 31 and 19 is 1.

M - Print a Multiplication Table
G - Find the Greatest Common Divisor
R - Raise a Number to a Power
Q - Quit

Enter your menu selection: r

Enter the base number: 4
Enter the power: 2

4 raised to the power 2 is 16.

M - Print a Multiplication Table
G - Find the Greatest Common Divisor
R - Raise a Number to a Power
Q - Quit

Enter your menu selection: R

Enter the base number: 5
Enter the power: 3

5 raised to the power 3 is 125.

M - Print a Multiplication Table
G - Find the Greatest Common Divisor
R - Raise a Number to a Power
Q - Quit

Enter your menu selection: T
T is not a valid menu choice.

M - Print a Multiplication Table
G - Find the Greatest Common Divisor
R - Raise a Number to a Power
Q - Quit

Enter your menu selection: y
Y is not a valid menu choice.

M - Print a Multiplication Table
G - Find the Greatest Common Divisor
R - Raise a Number to a Power
Q - Quit

Enter your menu selection: Q

Thank you for using Math Helper v0.1.

linux3[95]%

Submitting the Program

Here is a sample submission command. Note that the project name starts with uppercase 'P'.

submit cs104_101 Proj3 proj3.c

To verify that your project was submitted, you can execute the following command at the Unix prompt. It will show the file that you submitted in a format similar to the Unix 'ls' command.

submitls cs104_101 Proj3