Rosalind: de brujin graph

debrujin.pl

use strict;
use warnings;
my @sample = map { chomp; $_ } <>; #qw{TGAT CATG TCAT ATGC CATC CATC};

sub revc { my $_ = join '', reverse split //, shift; tr/ACGT/TGCA/; $_ }

my %SSrc;  $SSrc{$_}++ for @sample, map { revc($_) } @sample;

for (keys %SSrc) {
    printf "(%s, %s)\n", substr($_, 0, -1), substr($_, 1);
}