From: Xavier Noria <fxn@...>
Date: 2007-08-03T11:41:54+09:00
Subject: Re: Determining the common prefix for several strings

El Aug 3, 2007, a las 4:26 AM, Xavier Noria escribi�:

>   min_length = items.map {|i| i.length}.min
>   cuts = items.map {|i| i.split(//)[0, min_length]}
>   cuts.transpose.each_with_index do |t, i|
>     if t.uniq.length != 1
>       puts cuts.first[0, i].join('')
>       break
>     end
>   end

Hmmm, too convoluted. I realized you don't need the transpose and  
thus the min length and cuts if you go by columns in the loop. This  
is the same idea only more simple:

splits = items.map {|i| i.split(//)}
(0...splits.length).each do |i|
   if splits.map {|s| s[i]}.uniq.length != 1
     puts splits.first[0, i].join('')
     break
   end
end

-- fxn