1 files changed, 38 insertions, 0 deletions
diff --git a/challenge-070/perlboy1967/perl/ch-2.pl b/challenge-070/perlboy1967/perl/ch-2.pl
new file mode 100755
index 0000000000..edcf137275
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+++ b/challenge-070/perlboy1967/perl/ch-2.pl
@@ -0,0 +1,38 @@
+#!/usr/bin/perl
+
+# Perl Weekly Challenge - 070
+#
+# Task 2 - Gray Code Sequence
+#
+# Author: Niels 'PerlBoy' van Dijke
+
+use strict;
+use warnings;
+
+sub genGrayCodeSequence($);
+
+my ($N) = @ARGV;
+
+die "Argument must be a positive number"
+  unless ($N =~ m#^\d+$#);
+
+my @g = genGrayCodeSequence($N);
+
+printf q{
+Input: $N = %d
+Output: [%s]
+}, $N, join(', ', @g);
+
+sub genGrayCodeSequence($) {
+  my ($N) = @_;
+
+  my @g = (0, 1);
+
+  for my $i (2 .. $N) {
+    map { $_ = "0$_" } @g;
+    map { m/^.(.*)/; push(@g, "1$1") } reverse @g;
+  }
+
+  map { $_ = oct("0b$_") } @g;
+}
+