Merge pull request #6244 from polettix/polettix/pwc168

Add polettix's solution to challenge-168

8 files changed, 138 insertions, 0 deletions

diff --git a/challenge-168/polettix/blog.txt b/challenge-168/polettix/blog.txt
new file mode 100644
index 0000000000..f6337130ae
--- /dev/null
+++ b/challenge-168/polettix/blog.txt
@@ -0,0 +1 @@
+https://github.polettix.it/ETOOBUSY/2022/06/08/pwc168-perrin-prime/
diff --git a/challenge-168/polettix/blog1.txt b/challenge-168/polettix/blog1.txt
new file mode 100644
index 0000000000..ad226cc866
--- /dev/null
+++ b/challenge-168/polettix/blog1.txt
@@ -0,0 +1 @@
+https://github.polettix.it/ETOOBUSY/2022/06/09/pwc168-home-prime/
diff --git a/challenge-168/polettix/perl/ch-1.pl b/challenge-168/polettix/perl/ch-1.pl
new file mode 100644
index 0000000000..e4952fb0ed
--- /dev/null
+++ b/challenge-168/polettix/perl/ch-1.pl
@@ -0,0 +1,21 @@
+#!/usr/bin/env perl
+use v5.24;
+use warnings;
+use experimental 'signatures';
+no warnings 'experimental::signatures';
+
+use ntheory 'is_prime';
+
+my $n = shift // 13;
+say join ', ', perrin_primes($n);
+
+sub perrin_primes ($n) {
+   my @pps = (2, 3, 5);
+   my @state = (2, 5, 5);
+   while (@pps < $n) {
+      push @state, my $candidate = $state[0] + $state[1];
+      shift @state;
+      push @pps, $candidate if is_prime($candidate);
+   }
+   return @pps;
+}
diff --git a/challenge-168/polettix/perl/ch-2.pl b/challenge-168/polettix/perl/ch-2.pl
new file mode 100644
index 0000000000..24a1dd1255
--- /dev/null
+++ b/challenge-168/polettix/perl/ch-2.pl
@@ -0,0 +1,17 @@
+#!/usr/bin/env perl
+use v5.24;
+use warnings;
+use experimental 'signatures';
+no warnings 'experimental::signatures';
+
+use ntheory qw< factor >;
+
+my $n = shift // 10;
+say home_prime($n);
+
+sub home_prime {
+   my $next = join '', factor($_[0]);
+   return $next if $next eq $_[0];
+   $_[0] = $next;
+   goto &home_prime;
+}
diff --git a/challenge-168/polettix/perl/cpanfile b/challenge-168/polettix/perl/cpanfile
new file mode 100644
index 0000000000..94ac365d6f
--- /dev/null
+++ b/challenge-168/polettix/perl/cpanfile
@@ -0,0 +1 @@
+requires 'ntheory';
diff --git a/challenge-168/polettix/perl/cpanfile.snapshot b/challenge-168/polettix/perl/cpanfile.snapshot
new file mode 100644
index 0000000000..2fd600a3af
--- /dev/null
+++ b/challenge-168/polettix/perl/cpanfile.snapshot
@@ -0,0 +1,38 @@
+# carton snapshot format: version 1.0
+DISTRIBUTIONS
+  Math-Prime-Util-0.73
+    pathname: D/DA/DANAJ/Math-Prime-Util-0.73.tar.gz
+    provides:
+      Math::Prime::Util 0.73
+      Math::Prime::Util::ChaCha 0.73
+      Math::Prime::Util::Entropy 0.73
+      Math::Prime::Util::MemFree 0.73
+      Math::Prime::Util::PP 0.73
+      Math::Prime::Util::PrimeArray 0.73
+      Math::Prime::Util::PrimeIterator 0.73
+      ntheory 0.73
+    requirements:
+      Carp 0
+      Config 0
+      Exporter 5.57
+      ExtUtils::MakeMaker 0
+      Math::BigFloat 1.59
+      Math::BigInt 1.88
+      Math::Prime::Util::GMP 0.50
+      Tie::Array 0
+      XSLoader 0.01
+      base 0
+      constant 0
+      perl 5.006002
+  Math-Prime-Util-GMP-0.52
+    pathname: D/DA/DANAJ/Math-Prime-Util-GMP-0.52.tar.gz
+    provides:
+      Math::Prime::Util::GMP 0.52
+    requirements:
+      Carp 0
+      Exporter 5.57
+      ExtUtils::MakeMaker 0
+      Fcntl 0
+      XSLoader 0.01
+      base 0
+      perl 5.006002
diff --git a/challenge-168/polettix/raku/ch-1.raku b/challenge-168/polettix/raku/ch-1.raku
new file mode 100644
index 0000000000..28f3b1fb86
--- /dev/null
+++ b/challenge-168/polettix/raku/ch-1.raku
@@ -0,0 +1,28 @@
+#!/usr/bin/env raku
+use v6;
+
+class PerrinSequence {
+   has @!state = [3, 0, 2];
+   method get () {
+      @!state.push(@!state[0] + @!state[1]);
+      return @!state.shift;
+   }
+}
+
+multi sub MAIN (1) { put 2 }
+
+multi sub MAIN (2) { put '2, 3' }
+
+multi sub MAIN (3) { put '2, 3, 5' }
+
+multi sub MAIN (Int:D $n is copy where * > 3 = 13) {
+   my $ps = PerrinSequence.new;
+   $ps.get for 1..7;
+   my @n-primes = gather while $n > 3 {
+      my $candidate = $ps.get;
+      next unless $candidate.is-prime;
+      take $candidate;
+      --$n;
+   }
+   [2, 3, 5, |@n-primes].join(', ').put;
+}
diff --git a/challenge-168/polettix/raku/ch-2.raku b/challenge-168/polettix/raku/ch-2.raku
new file mode 100644
index 0000000000..5de2d6efd4
--- /dev/null
+++ b/challenge-168/polettix/raku/ch-2.raku
@@ -0,0 +1,31 @@
+#!/usr/bin/env raku
+use v6;
+sub MAIN (Int:D $n where * > 1 = 10) { put home-prime($n) }
+
+sub home-prime ($n is copy) {
+   loop {
+      my $m = factors($n).join('').Int;
+      return $n if $n == $m;
+      $n = $m;
+   }
+}
+
+sub factors (Int $remainder is copy) {
+   return 1 if $remainder <= 1;
+   state @primes = 2, 3, 5, -> $n is copy {
+      repeat { $n += 2 } until $n %% none @primes ... { $_ * $_ >= $n }
+      $n;
+   } ... *;
+   gather for @primes -> $factor {
+      if $factor * $factor > $remainder {
+         take $remainder if $remainder > 1;
+         last;
+      }
+
+      # How many times can we divide by this prime?
+      while $remainder %% $factor {
+         take $factor;
+         last if ($remainder div= $factor) === 1;
+      }
+   }
+}