my @flattened_array = flatten($nested_array_ref);

sub flatten {

    my $array = shift;
    my @results = ();

    foreach my $element ( @$array ) {

        if( ref $element eq 'ARRAY' ) {
            push @results, flatten($element);
        }
        elsif( $element ) {
            push @results, $element;
        }
    }

    return @results;
}