#!usr/bin/perl
use strict;
use warnings;
use Data::Dumper;
local our @deep;
local $; = ','; # A vestige of a previous version

my @data = qw(AAA ATG TTT GTC);
my @d2 = map [ split // ], @data;

my (%hash);
for my $entry (@d2) {
*deep = $entry;
for my $nx (0..$#deep) {
$hash{$deep[$nx]}[$nx]++;
}
}
foreach my $entry (values %hash) {
$entry = [ map defined $_ ? $_ : 0, @$entry ];
}
print Dumper(\%hash);