From f95f9de8bebf4967125de3a10999cbe524f9f1a3 Mon Sep 17 00:00:00 2001
From: Dave Jacoby <jacoby.david@gmail.com>
Date: Sat, 11 Jun 2022 18:02:10 -0400
Subject: Forgot to finish

---
 challenge-168/dave-jacoby/blog.txt     |  3 +++
 challenge-168/dave-jacoby/perl/ch-1.pl | 28 +++++++++++++++++++
 challenge-168/dave-jacoby/perl/ch-2.pl | 49 ++++++++++++++++++++++++++++++++++
 3 files changed, 80 insertions(+)
 create mode 100644 challenge-168/dave-jacoby/blog.txt
 create mode 100644 challenge-168/dave-jacoby/perl/ch-1.pl
 create mode 100644 challenge-168/dave-jacoby/perl/ch-2.pl

diff --git a/challenge-168/dave-jacoby/blog.txt b/challenge-168/dave-jacoby/blog.txt
new file mode 100644
index 0000000000..b28b04f643
--- /dev/null
+++ b/challenge-168/dave-jacoby/blog.txt
@@ -0,0 +1,3 @@
+
+
+
diff --git a/challenge-168/dave-jacoby/perl/ch-1.pl b/challenge-168/dave-jacoby/perl/ch-1.pl
new file mode 100644
index 0000000000..39a1510b86
--- /dev/null
+++ b/challenge-168/dave-jacoby/perl/ch-1.pl
@@ -0,0 +1,28 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use experimental qw{ say postderef signatures state };
+
+my @perrin = ( 3, 0, 2 );
+my %perrin_primes;
+$perrin_primes{2} = 1;
+$perrin_primes{3} = 1;
+
+while ( scalar keys %perrin_primes < 13 ) {
+    my $x = $perrin[-2] + $perrin[-3];
+    push @perrin, $x;
+    $perrin_primes{$x} = 1 if is_prime($x);
+}
+
+say join ' ', sort { $a <=> $b } keys %perrin_primes;
+exit;
+
+sub is_prime ($n) {
+    die "Bad number $n" unless length $n;
+    return 0 if $n == 0;
+    return 0 if $n == 1;
+    for ( 2 .. sqrt $n ) { return 0 unless $n % $_ }
+    return 1;
+}
+
diff --git a/challenge-168/dave-jacoby/perl/ch-2.pl b/challenge-168/dave-jacoby/perl/ch-2.pl
new file mode 100644
index 0000000000..1d101a36a4
--- /dev/null
+++ b/challenge-168/dave-jacoby/perl/ch-2.pl
@@ -0,0 +1,49 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use experimental qw{ say postderef signatures state };
+
+use Carp;
+use Try::Tiny;
+use Math::Prime::XS qw{ is_prime };
+
+$| = 1;
+
+my @n = @ARGV;
+push @n, 10 unless scalar @ARGV;
+
+for my $i (@n) {
+    try {
+        my $p = get_home_prime($i);
+        say join "\t", '-', $i, $p;
+    }
+    catch {
+        say $_;
+    };
+}
+
+sub get_home_prime($n) {
+    my $p = $n;
+    while ( !is_prime($p) ) {
+        my @factors = get_factors($p);
+        $p = join '', @factors;
+        print qq{$p };
+        # croak 'Too Big, Too Slow' if length $p > 10;
+    }
+    say '';
+    return $p;
+}
+
+sub get_factors( $n ) {
+    my @factors;
+    for my $i ( 2 .. $n ) {
+        next unless $n % $i == 0;
+        while ( $n % $i == 0 ) {
+            push @factors, $i;
+            $n = $n / $i;
+        }
+    }
+    return @factors;
+}
+
-- 
cgit