#!/usr/bin/env perl -l

use strict;
use warnings;

my %comp = qw{A T C G G C T A a t c g g c t a};
my $seq = 'ACGTacgt';
print 'Initial:            ', $seq;
print 'Complement:         ', @comp{split '' => $seq};
print 'Reverse Complement: ', @comp{reverse split '' => $seq};

##</code><code>##

Initial:            ACGTacgt
Complement:         TGCAtgca
Reverse Complement: acgtACGT

##</code><code>##

my @n = split '' => $seq;
print 'Complement:         ', @comp{@n};
print 'Reverse Complement: ', @comp{map { $n[$#n - $_] } 0 .. $#n};