From: Adam Shelly <adam.shelly@...>
Date: 2006-07-16T06:34:07+09:00
Subject: Re: Who likes Sudoku?

On 7/15/06, Adam Shelly <adam.shelly@gmail.com> wrote:
> Yes, before we golf this further, does it even work?

oops, my mistake.  I was giving it a filename containing a puzzle on
the command line instead of the puzzle itself.  It does run and
converge - but it leaves the last digit 0 unless you make the outer
loop 81.times.   Here's what I've got - I mapped the input to
integers, which removed a bunch of 'to_i's.
def s; h={}
  81.times{|j| next if $p[j]>0
    80.times {|k| h[$p[k]] = 1 if k/9==j/9 || k%9==j%9 || k/27==j/27
&& k%9/3==j%9/3}
    1.upto(9){|v| $p[j]=v and s unless h[v]}
    return $p[j]=0; }
  p "Solution: #{$p}"
end;
$p = $*[0].split('').map{|v|v.to_i}; s