From: Matthew Moss <matthew.moss@...>
Date: 2008-07-12T00:17:15+09:00
Subject: [QUIZ] Symbolify (#169)

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

The three rules of Ruby Quiz 2:

1.  Please do not post any solutions or spoiler discussion for this
quiz until 48 hours have passed from the time on this message.

2.  Support Ruby Quiz 2 by submitting ideas as often as you can! (A
permanent, new website is in the works for Ruby Quiz 2. Until then,
please visit the temporary website at

     <http://splatbang.com/rubyquiz/>.

3.  Enjoy!
Suggestion:  A [QUIZ] in the subject of emails about the problem
helps everyone on Ruby Talk follow the discussion.  Please reply to
the original quiz message, if you can.

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

## Symbolify (#169)

Your task this week is to count. Yup, that's it.

Oh, by the way... You may only use the characters `?`, `*`, `(`, `)` and `-`.

Specifically, define a function `symbolify` that accepts an integer
and returns a string composed of only the five characters shown above.
The string, when evaluated, will equal the original number passed in.

That is, the following test code should raise no exceptions:

    1000.times do |i|
      s = symbolify(i)
      raise "Not a string!"  unless s.is_a? String
      raise "Invalid chars!" unless s.delete("?*()-").empty?

      x = eval(s)
      raise "Decode failed!" unless i == x
    end


There are at least a few different approaches that come to mind, so
don't expect everyone to have the same output. Well, not before the
output is passed through `eval`, that is.

I am not requiring that you produce the shortest string (though you
are welcome to attempt such a thing). The only thing I _do_ ask is
that you not produce megabytes of data to represent a simple integer.

P.S. Cheating is encouraged (except that you may not write code
outside of `symbolify`).



-- 
Matthew Moss <matthew.moss@gmail.com>