From: Aldric Giacomoni <aldric@...>
Date: 2009-12-19T01:57:39+09:00
Subject: Re: Unique combination of values from arrays

Aldric Giacomoni wrote:
> Giampiero Zanchi wrote:
>> one = ['one', 'two']
>> two = ['three', 'four']
>> three = ['five', 'six']

Sorry for the spam, just wanted to repost the cleaner solutions:

Mine first, of course, because it is ugly:

def array_permutations array, index=0
  # index is 0 by default : start at the beginning, more elegant.
  return array[-1] if index == array.size - 1 # Return last element if 
at end.
  result = []
  array[index].each do |element| # For each array
    array_permutations(array, index + 1).each do |x| # Permute permute 
permute
      result << "#{element}, #{x}"
    end
  end
  return result
end

My adaptation of Giampiero's solution:

def fancy_array_permutation array
  return array[0] if array.size == 1
  first = array.shift
  return first.product( fancy_array_permutation(array) ).map {|x| 
x.flatten.join(" ")}
end
-- 
Posted via http://www.ruby-forum.com/.