use strict;
use warnings;
use Data::Dumper;

my @sorted = qw(1.2.3 a.b.c literal.b.c);
my @array1;
my @array2;
my @array3;

foreach my $results (@sorted) {                                         
    my @listOfItems = split( /\./, $results);

    if ( $listOfItems[0] =~ /literal/ ) {
        $listOfItems[0] = join(".", @listOfItems[0..1]);                    
    }
  
    push (@array1, $listOfItems[0]);
    push (@array2, $listOfItems[1]);
    push (@array3, $listOfItems[2]);

    # @array1 should contain the newly conjoined $listOfItems[0]

}

print Dumper \@array1;