my %cache;
find({wanted => \&ab_wanted, no_chdir => 1}, $opt{d});

use Data::Dumper;
print Dumper \%files, \%cache;

sub ab_wanted {
    if (-r _ && -f _){
        $size = int ((-s _) / 2**20);
        if ($size > $opt{s} && $opt{a} < -A _){
            $uid = (lstat(_))[4];
            my $name = $cache{$uid};
            unless (defined $name) {
                $name = getpwuid($uid);
                $cache{$uid} = $name;  
            }
            push @{$files{$name}}, [ $_, $size, int -A _ ];
        }
    }
}