mhriess

#  Put your answers here!

Michael-Riess-Computer:~ michaelriess$ rvm list

rvm rubies

   ruby-1.8.7-p302 [ i686 ]
   ruby-1.9.2-p290 [ x86_64 ]
=* ruby-1.9.2-p318 [ x86_64 ]
   ruby-1.9.2-p320 [ x86_64 ]

mhriess

Create an RPNCalculator class which can evaluate expressions
written in Reverse Polish notation.

It should have an evaluate instance method which takes as its 
input a valid RPN expression and returns its evaluation. Your 
calculator only needs to handle addition, multiplication, and 
subtraction (not division).

Operators and numbers should be separated by a single space.

mhriess

Write a method mode which takes an Array of numbers
as its input and returns an Array of the most frequent values.

If there's only one most-frequent value, it returns a
 single-element Array.

For example,

mode([1,2,3,3])         # => [3]
mode([4.5, 0, 0])       # => [0]