From: Pierre-Charles David <Pierre-Charles.David@...>
Date: 2001-10-09T18:01:22+09:00
Subject: [ruby-talk:22291] Re: [Newbie] Switching from Perl : suffling

Frykholm, Niklas wrote:

> [Pierre-Charles David]
> 
>>One of my teachers once showed me this method, which I find quite 
>>elegant (although perhaps not very efficient because of the arrays 
>>creation, but still O(n) ):
>>
>>module Enumerable
>>  def shuffle
>>    # Associate a random number to each element
>>    pairs = self.collect { |item| [rand(), item] }
>>    # Sort the pairs according to the random part
>>    # and extract the original data
>>    (pairs.sort { |x, y| x[0] <=> y[0] }).collect { |pair| pair[1] }
>>  end
>>end
>>
> 
> Sorting is O(n log n).


Yes! How stupid of me...

-- 
Pierre-Charles David (pcdavid <at> emn <dot> fr)
Computer Science PhD Student, �cole des Mines de Nantes, France
Homepage: http://purl.org/net/home/pcdavid