For those that don't know, a grey coded list of numbers has all numbers with a given number of bits, ordered such that there is exactly one bit changed from each item to the next, including from the first to the last item. For example, the cannonical 2 bit grey code is

00
01
11
10

The goal is to return a list ref to a list of strings comprising a grey code list for a given number of bits. Note that by strings I mean a series of ascii 1's and 0's, not the actual binay data.

My solution comes in at 101 chars: 
sub grey
{
$b=shift;
for $c (0..2**$b-1){for(-$b..-1){
$l[$c].=($c&1<<-$_-1)>>-$_-1^($c&1<<-$_)>>-$_;}}
return \@l;
}

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'The fickle fascination of and Everlasting God' - Billy Corgan, The Smashing Pumpkins

In reply to (Golf) Grey code by Everlasting God

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