From: Christer Nilsson Date: 2005-12-14T01:56:49+09:00 Subject: Re: Array.invert Kroeger, Simon (ext) wrote: > Hi Christer, > > don't take this to serious: > > a = [[1,3],[1,4,5]] > p (0...a.size).zip(a).inject([]){|s, b| b[1].each{|i| (s[i] ||= []) << > b[0]}; s} > > => [nil, [0, 1], nil, [0], [1], [1]] > > cheers > > Simon Is it possible to wrap this in a method ? I tried but I get a nil.each error. Christer -- Posted via http://www.ruby-forum.com/.