#!/usr/bin/perl -w
use strict;
my @array        = qw(0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20);
my $rows          = 2;
my $row_count  = 0;
my $array_total = 7;
 
print "[START]\n"; 
for(my $i = 1; $array_total >= $i; ++$i) {
    if ($row_count == 0) {
        $row_count += 2;
        print "$array[$i] ";
    } elsif ($i == $array_total) {
        print "$array[$i]";
    } elsif ($rows == $row_count) {
        $row_count = 0;
        print "$array[$i]\n";
    } else {
        ++$row_count;
        print "$array[$i] ";
    }
}   
print "\n[END]\n";