Since you seemed interested.. here is my permutation generator.
It takes a base string (should be empty) as its first
argument, then refrences to as many lists as you want
as the other arguments and returns a refrence to a list
containg all the list-element concatination permutations:
my $foo=permute('',[0..2],[0..2],[0..3],[0..2]);
sub permute{
my $prefix=shift;
my @arrays=@_;
my $c=shift @arrays;
my @ret=();
foreach(@$c){
my $f=$prefix.$_;
if(scalar(@arrays)==0){
push @ret,$f;
}else{
my $t=permute($f,@arrays);
push @ret,@$t;
}
}
return \@ret;
}
I'm not really happy with the implementation of it, but
I like it in spirit (of course, I'm a big fan of recursive
algorithms to begin with).