# my $n              = 5;
    my @set;
    my $file_count;
    my $partition_size;
    my $remainder;

    $file_count     = scalar @file;                   # 12
    if ( $file_count >= $n ) {
        $partition_size = int( $file_count / $n );    # 2
        $remainder      = $file_count % $n;           # 2
    }
    else {
        $partition_size = 1;
        $remainder = 0;
    }
    my $i = 0;
    while ( scalar @file ) {
        foreach my $j ( 1 .. $partition_size ) {
            my $fn = shift @file;
            push @{$set[$i]}, $fn;
        }
        if ( $i < $remainder ) {
            my $fn = shift @file;
            push @{$set[$i]}, $fn;
        }
        $i++;
    }