natural sort in perl

natural_sort.pl

sub mycmp {
    my $an = @{$a->[1]}+@{$a->[2]};
    my $bn = @{$b->[1]}+@{$b->[2]};
    my $n = $an<$bn ? $an : $bn;
    foreach my $i (0..$n-1) {
        my $aa = $a->[$i%2+1][$i/2];
        my $bb = $b->[$i%2+1][$i/2];
        my $res = $aa=~/^\d+$/ && $bb=~/^\d+$/ ? $aa <=> $bb : $aa cmp $bb;
        return $res if ($res!=0);
    }
    return -1 if ($an<$bn);
    return +1 if ($an>$bn);
    return 0;
}

@sorted=sort mycmp (map {
    /^\d/
        ? [$_,[split /\D+/],[split /\d+/]]
        : [$_,[split /\d+/],[split /\D+/]]
} <>);

print $_->[0] for @sorted;