2 files changed, 70 insertions, 0 deletions
diff --git a/challenge-120/pete-houston/perl/ch-1.pl b/challenge-120/pete-houston/perl/ch-1.pl
new file mode 100644
index 0000000000..9c0862db3e
--- /dev/null
+++ b/challenge-120/pete-houston/perl/ch-1.pl
@@ -0,0 +1,24 @@
+#!/usr/bin/env perl 
+#===============================================================================
+#
+#         FILE: 12001.pl
+#
+#        USAGE: ./12001.pl N 
+#
+#  DESCRIPTION: Swap the odd bits with the even ones.
+#
+# REQUIREMENTS: N must be an integer between 0 and 255 inclusive
+#       AUTHOR: Pete Houston (pete), cpan@openstrike.co.uk
+# ORGANIZATION: Openstrike
+#      VERSION: 1.0
+#      CREATED: 05/07/21
+#===============================================================================
+
+use strict;
+use warnings;
+
+my $n        = shift;
+my %masks    = ( even => 0b10101010, odd => 0b01010101 );
+my $swapped  = ($n & $masks{even}) / 2 + ($n & $masks{odd}) * 2;
+
+print "$swapped\n";
diff --git a/challenge-120/pete-houston/perl/ch-2.pl b/challenge-120/pete-houston/perl/ch-2.pl
new file mode 100644
index 0000000000..36c22fceab
--- /dev/null
+++ b/challenge-120/pete-houston/perl/ch-2.pl
@@ -0,0 +1,46 @@
+#!/usr/bin/env perl 
+#===============================================================================
+#
+#         FILE: 12002.pl
+#
+#        USAGE: ./12002.pl HH:MM 
+#
+#  DESCRIPTION: Print the non-reflex angle in degrees between the clock hands
+#
+# REQUIREMENTS: IO::All and a UTF-8 compatible terminal
+#        NOTES: There is AFAICT no term for an angle less than pi.
+#       AUTHOR: Pete Houston (pete), cpan@openstrike.co.uk
+# ORGANIZATION: Openstrike
+#      VERSION: 1.0
+#      CREATED: 05/07/21
+#===============================================================================
+
+use strict;
+use warnings;
+
+use IO::All -utf8;
+
+my ($h, $m) = get_input ();
+
+my $minfrac   = $m / 60;
+my $hfrac     = ($h + $minfrac) / 12;
+my $fracdiff  = abs ($hfrac - $minfrac);
+
+# Ensure we are using the non-reflex angle
+$fracdiff = 1 - $fracdiff if $fracdiff > 0.5;
+
+# Convert fraction into angle
+my $diffang = $fracdiff * 360;
+my $deg     = int $diffang;
+my $min     = ($diffang - $deg) * 60;
+
+my $fmt = "At %2.2i:%2.2i, the angle between the hands is " .
+	"%i\N{DEGREE SIGN} %.0f'\n"; 
+printf $fmt, $h, $m, $deg, $min;
+
+sub get_input {
+	my $in = shift @ARGV;
+	$in =~ /^([012]?[0-9]):([0-5][0-9])$/ or
+		die "'$in' is not a valid time in HH:MM format.\n";
+	return ($1 % 12, $2);
+}