- Added solutions by Pete Houston.

3 files changed, 127 insertions, 0 deletions

diff --git a/challenge-164/pete-houston/lua/ch-2.lua b/challenge-164/pete-houston/lua/ch-2.lua
new file mode 100755
index 0000000000..24b7817fcb
--- /dev/null
+++ b/challenge-164/pete-houston/lua/ch-2.lua
@@ -0,0 +1,42 @@
+#!/usr/bin/env lua

+--[[

+#===============================================================================

+#

+#         FILE: 16402.lua

+#

+#        USAGE: ./16402.lua N

+#

+#  DESCRIPTION: First N decimal Happy numbers

+#

+#        NOTES: N must be a natural number

+#       AUTHOR: Pete Houston (pete), cpan@openstrike.co.uk

+# ORGANIZATION: Openstrike

+#      VERSION: 1.0

+#      CREATED: 13/05/22

+#===============================================================================

+]]

+

+function is_happy (x) 

+	local seen = {}

+	seen[x] = 1

+	while x ~= 1 do

+		sum = 0

+		for c in string.gmatch (x, "%d") do

+			sum = sum + c * c

+		end

+		if seen[sum] then return 0 end

+		seen[sum] = 1

+		x = sum

+	end

+	return 1

+end

+

+m = tonumber (arg[1])

+i = 1

+while m > 0 do

+	if is_happy (i) == 1 then

+		print (i)

+		m = m - 1

+	end

+	i = i + 1

+end

diff --git a/challenge-164/pete-houston/perl/ch-1.pl b/challenge-164/pete-houston/perl/ch-1.pl
new file mode 100755
index 0000000000..563a5f12e8
--- /dev/null
+++ b/challenge-164/pete-houston/perl/ch-1.pl
@@ -0,0 +1,33 @@
+#!/usr/bin/env perl
+#===============================================================================
+#
+#         FILE: 16401.pl
+#
+#        USAGE: ./16401.pl [ N ]
+#
+#  DESCRIPTION: Palindromic primes up to N (default 999)
+#
+#      OPTIONS: N defaults to 999 if unset
+# REQUIREMENTS: Math::Prime::Util
+#       AUTHOR: Pete Houston (pete), cpan@openstrike.co.uk
+# ORGANIZATION: Openstrike
+#      VERSION: 1.0
+#      CREATED: 09/05/22
+#===============================================================================
+
+use strict;
+use warnings;
+
+use Math::Prime::Util 'is_prime';
+
+my $max = shift // 999;
+die "Argument must be natural number.\n" unless $max =~ /^[1-9][0-9]*$/;
+
+my @pp;
+
+for my $n (2 .. $max) {
+	next unless $n eq reverse $n;
+	push @pp, $n if $n eq reverse $n && is_prime ($n);
+}
+
+print "@pp\n";
diff --git a/challenge-164/pete-houston/perl/ch-2.pl b/challenge-164/pete-houston/perl/ch-2.pl
new file mode 100755
index 0000000000..8a706693c4
--- /dev/null
+++ b/challenge-164/pete-houston/perl/ch-2.pl
@@ -0,0 +1,52 @@
+#!/usr/bin/env perl
+#===============================================================================
+#
+#         FILE: 16402.pl
+#
+#        USAGE: ./16402.pl [ N ]
+#
+#  DESCRIPTION: Print out the first N decimal happy numbers.
+#
+#      OPTIONS: N defaults to 8 if unset
+# REQUIREMENTS: Perl 5.10.0 for //
+#       AUTHOR: Pete Houston (pete), cpan@openstrike.co.uk
+# ORGANIZATION: Openstrike
+#      VERSION: 1.0
+#      CREATED: 13/05/22
+#===============================================================================
+
+use strict;
+use warnings;
+
+my $n = shift // 8;
+die "Argument must be natural number.\n" unless $n =~ /^[1-9][0-9]*$/;
+
+my @happy;
+my $i = 1;
+
+while ($n > @happy) {
+	push @happy, $i if is_happy ($i);
+	$i++;
+}
+
+print "@happy\n";
+
+sub is_happy {
+	my $x    = shift;
+	my %seen = ($x => 1);
+
+	while ($x != 1) {
+
+		# Sum the squares of the digits
+		my $sum = 0;
+		$sum += chop ($x) ** 2 for 1 .. length $x;
+
+		# Have we looped?
+		return 0 if $seen{$sum};
+
+		# Store it and go again
+		$seen{$x = $sum} = 1;
+	}
+
+	return 1;
+}