From: gabriele renzi <surrender_it@...>
Date: 2005-12-07T02:47:34+09:00
Subject: Re: Good Ruby Examples?

Wayne Vucenic ha scritto:
> Hi Hampton,
> 
> 
>>What I'm asking you guys for is if you have any short code ideas that
>>can be programmed *really* quickly in Ruby that might illustrate its
>>versatility. Some code example that would be hell to write in other
>>languages that would be interesting for an hour long explaination.
> 
> 
> My favorite is the well-known quicksort algorithm:
> 
> def quicksort(a)
>   return a if a.size <= 1
>   pivot = a[0]
>   quicksort(a.select {|i| i < pivot }) +
>             a.select {|i| i == pivot } +
>   quicksort(a.select {|i| i > pivot })
> end
> 
> quicksort is "hell" to write in C or C++ unless you're extremely clever.

you may appreciate Enumerable#partition:
def qs(a)
   return a if a.size <=1
   pivot = a.shift
   less, more = a.partition{|y| y < pivot}
   qs(less) + [pivot] + qs(more)
end