Recursive Math

Due Time/Date:	Friday April 12th., 2002 at 10:00 p.m. UH-UNIX time.
What to do:	Write at least one class. The name of your application should be RecursiveMath. There is no need to append anything to the class name since it is not an applet.
How to turn in your homework?	Send e-mail to ics211-homework@hawaii.edu. attaching the JAVA file. If you created any extra classes for this assignment, you must submit them as well. All these classes should be attached to your e-mail. The subject of your e-mail must be "Recursive Math". No zip files will be accepted. If any files arrived in zip format they will be discarded and you will get no credit for your work. Please make sure that your program compiles/runs properly in UH-UNIX.
Comments	Please comment all your classes and methods with a brief description of what each method does. Remember that nothing is obvious. Do not forget to add your your name to your program code.

Program requirements and structure

Your program should contain no "for" nor "while" loops, all the looping SHOULD be done using recursion.

Note that the specified menu should be recursive as well, and it should display the following options:

add (two numbers)
subtract (two numbers)
multiply (two numbers)
divide (two numbers)
power (two numbers)
factorial (one number)
summation (one number)
exit

Each one of these options should call a recursive method to perform the selected math operation. You may use the code from class.

Recursive Methods that your class should contain :

Given the fact that the methods listed are only the methods' names, it is VERY important that you add explicit comments to your code. Note that neither the return values, neither the arguments are specified, this is for you to specify and comment.

Method	Restrictions
add	Two numbers are given. Addition must be done with a recursive method that will increment by one every time.
subtract	Two numbers are given. Subtraction must be done with a recursive method that will decrement by one every time. The subtraction may result in a negative number.
multiply	Two numbers are given. Multiplication should be done by successive additions. This method does not need to call upon the add method.
divide	Two numbers are given. This method should implement integer division. Division should be done by successive subtractions. This method does not need to call upon the subtract method. Division can not result in a negative number.
power	The first number should be elevated to the power of the second number.
factorial	One number should be given and the factorial of it should be calculated.
summation	Given one number N the summation from 1 to N should be calculated

Your program should verify that the options entered are valid (A number from 1 to 8)
You must verify that all the numbers that will be used in any of the previously described methods are positive integers, zero included. The upper limit for the factorial is 25. For the rest of the methods there is no upper limit. You must verify this as well.
You should try/catch for exception handling. From this assignment on, any uncaught exception will result in a deduction of up to 10 points.

Why do this assignment?

You will practice/learn:

Using recursion.
Practice your skills in command line interfaces and menus.

If you have any more questions please e-mail blanca@hawaii.edu