From: "trans.  (T. Onoma)" <transami@...>
Date: 2004-12-14T08:55:45+09:00
Subject: Re: Help writing a each_unique method

On Monday 13 December 2004 04:12 pm, Andrew Johnson wrote:
| One way:
|
|   class Array
|     def each_combination(k)
|       n = self.size
|       return unless (1..n) === k
|       idx = (0...k).to_a
|       loop do
|         yield self.values_at(*idx)
|         i  = k - 1
|         i -= 1 while idx[i] == n - k + i
|         break if i < 0
|         idx[i] += 1
|         (i + 1 ... k).each {|j| idx[j] = idx[i] + j - i}
|       end
|     end
|   end
|
|   a = %w|a b c d e|
|   n = 3
|   a.each_combination(3) do |c|
|     p c
|   end

Perfect. Thanks. Think #each_combination is best name?

T.