my %hash = map {($part1[$_] => [$part2[$_], $gp_ids[$_]])}0..$#part1;

#print "$#island_ids $#nonisland_ids $#plasmid_ids\n";

my %map;
@map{@island_ids}  = ("island")     x @island_ids;
@map{@nonisland_ids} = ("nonisland")    x @nonisland_ids;
@map{@plasmid_ids}  = ("plasmid")     x @plasmid_ids;

while (my($k,$v) = each %hash) {
 print "$map{$k}-$map{$v->[0]}  $map{$v->[1]}\n";
}

use Data::Dumper;
print Dumper \%hash;

# output from hash:
island-plasmid
plasmid-island
plasmid-island
island-nonisland
plasmid-island


# output from Dumper:
          'c6679893-6679264
' => [
                                   '39687-39872
',
                                   '1'
                                 ],
          'c4702714-4702079
' => [
                                   'c78072-77437
',
                                   '138'
                                 ],