This solution is almost similar to other ones supplied by other monks:

#!/bin/perl

my @array = qw(1 2 3 4 5 6 7 8 9 10 11 12);

my $data;

my $div = 4;

for my $i ( @array ) {
    my $j = $i % $div;
    push @{ $data->{$j || $div} }, $i;
}

use Data::Dumper;
print Dumper \@array;
print Dumper $data;
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