From: Todd Benson <caduceass@...>
Date: 2007-12-02T08:30:58+09:00
Subject: Re: Postfix to Infix (#148)

On Dec 1, 2007 5:05 PM, Eric I. <rubytraining@gmail.com> wrote:
> On Dec 1, 5:27 pm, Todd Benson <caduce...@gmail.com> wrote:
> > On Dec 1, 2007 4:18 PM, Daniel Martin <mar...@snowplow.org> wrote:
> >
> > > "Christian von Kleist" <cvonkle...@gmail.com> writes:
> > > But:
> >
> > > '1 2 - 3 4 - -' should become '1 - 2 - (3 - 4)'
> >
> > Or '1 - 2 - 3 + 4'  (yikes!) :^0
>
> Well one feature of the Ruby Quiz is that our Quiz Master generally
> allows submitters quite a bit of flexibility in reinterpreting the
> problem.  To me, however, that form seems outside the problem
> description, as you're a) applying the distributive property, and b)
> ending up with a different set of operators than what you started with
> (from 3 minuses to 2 minuses and 1 plus).
>
> And once you start down the road '4 2 3 + *' could become '4 * (2 +
> 3)', '8 + 12', or even '20'.
>
> Eric

Of course.  It's not a quiz about simplification.  I just thought it
was funny (a stretch on the minimizing of parentheses).  It keeps the
same digits, though; only changes the operators.  It's quite clear
that the only symbols -- digits or operators -- we're allowed to add
or remove are ) and (.

Cheers,
Todd