Multiplication, Recursively

The goal for this exercise is to practice writing (increasingly complex) recursive code.

 

For this exercise, you need to implement the MultR method in the provided RecursiveMethods class.   

This class should be found in the Student_Answers.cs file.  The method  should take two integer parameters, and will return the product of them.  You're not allowed to simply multiply the two numbers inside the function, and return the value, though – you need to find a way, by using simpler mathematical operations on the values that you pass to the successive recursive calls, to get this to happen.  MultR needs to correctly calculate the result of multiplying any two whole numbers – positive, negative, and zero.

What you need to do for this exercise: 

1. Implement MultR, as described above
   1. Note that the best way to approach this is to have two methods – a public method that other classes are intended to call (that handles any one-time, "initialization" type work), and a private method (this is the one that's actually recursive)
2. Once you’ve completed the above task, you should run the tests in the NUnit_Tests_Recursive_Multiplication class.  They should all pass at this point, and if not, then you should fix your program so that those tests do pass.