From: Phrogz <phrogz@...>
Date: 2007-09-11T00:50:07+09:00
Subject: Re: Count and Say (#138)

On Sep 10, 6:23 am, Simon Kr�ger <SimonKroe...@gmx.de> wrote:
> class String
>   def look_and_say
>     gsub(/(.)\1*/){|s| "#{s.size}#{s[0,1]}"}
>   end
> end

Dude, that's elegant. Thanks for sharing. I particularly like keeping
it as a String, avoiding the performance issues of Bignum for the
truly large.

Your solution scales much, much better than mine after a few
iterations:

                    user     system      total        real
Simon up to 30  0.203000   0.000000   0.203000 (  0.219000)
Gavin up to 30  0.500000   0.000000   0.500000 (  0.531000)

Simon up to 32  0.390000   0.000000   0.390000 (  0.407000)
Gavin up to 32  0.672000   0.000000   0.672000 (  0.672000)

Simon up to 34  0.485000   0.000000   0.485000 (  0.484000)
Gavin up to 34  1.578000   0.000000   1.578000 (  1.579000)

Simon up to 36  0.750000   0.016000   0.766000 (  0.765000)
Gavin up to 36  4.000000   0.000000   4.000000 (  4.032000)

Simon up to 38  1.328000   0.000000   1.328000 (  1.328000)
Gavin up to 38 10.312000   0.094000  10.406000 ( 10.471000)

Simon up to 40  2.500000   0.015000   2.515000 (  2.531000)
Gavin up to 40 28.016000   0.031000  28.047000 ( 28.270000)

Simon up to 42  4.375000   0.079000   4.454000 (  4.485000)
Gavin up to 42 80.219000   0.046000  80.265000 ( 81.029000)