use strict;
use warnings;

my @matrix = (
    {A => 4,  C => 0,  G => 13, T => 0},
    {A => 5,  C => 0,  G => 12, T => 0},
    {A => 15, C => 0,  G => 2,  T => 0},
    {A => 0,  C => 17, G => 0,  T => 0},
);

for my $h (0..$#matrix) {
    my @temp;
    print "[ $h ";
    for my $k (sort {$matrix[$h]->{$b} <=> $matrix[$h]->{$a}} (keys(%{$matrix[$h]}))) {
        print "$matrix[$h]->{$k} ";
        push @temp, $k
    }
    print "@temp ]\n"
}