From: Martin Boese <boesemar@...>
Date: 2008-07-14T15:49:41+09:00
Subject: Re: [QUIZ] Symbolify (#169)

My previous post didn't work for i=0, this one does:

def symbolify(i)
"??-??"+"--?)-?("*i
end

On Sunday 13 July 2008 18:18:12 Martin Boese wrote:
> My solution:
>
> def symbolify(i)
> ("?)-?(--"*i)[0..-3]
> end
>
> However, at about 3300 I get a SystemStackError and if I start at like 5000
> I segfault the ruby interpreter (1.8.6) ;-)
>
> martin
>
> On Friday 11 July 2008 16:17:15 Matthew Moss wrote:
> > -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
> >
> > 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`).