Merge pull request #2698 from polettix/polettix/pwc085

Add polettix's solution to challenge 085

7 files changed, 71 insertions, 0 deletions

diff --git a/challenge-085/polettix/blog.txt b/challenge-085/polettix/blog.txt
new file mode 100644
index 0000000000..96890d360f
--- /dev/null
+++ b/challenge-085/polettix/blog.txt
@@ -0,0 +1 @@
+https://github.polettix.it/ETOOBUSY/2020/11/05/pwc085-triplet-sum/
diff --git a/challenge-085/polettix/blog1.txt b/challenge-085/polettix/blog1.txt
new file mode 100644
index 0000000000..0eea5045da
--- /dev/null
+++ b/challenge-085/polettix/blog1.txt
@@ -0,0 +1 @@
+https://github.polettix.it/ETOOBUSY/2020/11/06/pwc085-power-of-two-integer/
diff --git a/challenge-085/polettix/perl/.gitignore b/challenge-085/polettix/perl/.gitignore
new file mode 100644
index 0000000000..2c553cb420
--- /dev/null
+++ b/challenge-085/polettix/perl/.gitignore
@@ -0,0 +1 @@
+/local
diff --git a/challenge-085/polettix/perl/ch-1.pl b/challenge-085/polettix/perl/ch-1.pl
new file mode 100644
index 0000000000..300dad4f20
--- /dev/null
+++ b/challenge-085/polettix/perl/ch-1.pl
@@ -0,0 +1,23 @@
+#!/usr/bin/env perl
+use 5.024;
+use warnings;
+use experimental qw< postderef signatures >;
+no warnings qw< experimental::postderef experimental::signatures >;
+
+use FindBin '$Bin';
+use lib "$Bin/local/lib/perl5";
+
+use Math::Combinatorics ();
+
+sub triplet_sum {
+   my @R = grep { $_ <= 2.0 } @_; # remove cruft
+   my $combiner = Math::Combinatorics->new(count => 3, data => \@R);
+   while (my ($x, $y, $z) = $combiner->next_combination) {
+      $x += $y + $z;
+      return 1 if 1 <= $x && $x <= 2;
+   }
+   return 0;
+};
+
+my @input = scalar @ARGV ? @ARGV : (0.5, 1.1, 0.3, 0.7);
+say triplet_sum(@input);
diff --git a/challenge-085/polettix/perl/ch-2.pl b/challenge-085/polettix/perl/ch-2.pl
new file mode 100644
index 0000000000..90e5644cd2
--- /dev/null
+++ b/challenge-085/polettix/perl/ch-2.pl
@@ -0,0 +1,36 @@
+#!/usr/bin/env perl
+use 5.024;
+use warnings;
+use experimental qw< postderef signatures >;
+no warnings qw< experimental::postderef experimental::signatures >;
+
+sub factor ($N) {
+   my %retval;
+   my @ps = (2, 3);
+   my $k = 1;
+   while ($N > 1) {
+      if (! @ps) {
+         push @ps, 6 * $k - 1, 6 * $k + 1;
+         $k++;
+      }
+      my $p = shift @ps;
+      while ($N % $p == 0) {
+         $retval{$p}++;
+         $N /= $p;
+      }
+   }
+   return \%retval;
+}
+
+sub power_of_two_integers ($N) {
+   my $factors = factor($N);
+   my ($min, @others) = sort {$a <=> $b} values $factors->%*;
+   return 0 if $min == 1;
+   for my $exponent (@others) {
+      return 0 if $exponent % $min;
+   }
+   return 1;
+}
+
+my $N = shift // 8;
+say power_of_two_integers($N);
diff --git a/challenge-085/polettix/perl/cpanfile b/challenge-085/polettix/perl/cpanfile
new file mode 100644
index 0000000000..0b9147b47a
--- /dev/null
+++ b/challenge-085/polettix/perl/cpanfile
@@ -0,0 +1 @@
+requires 'Math::Combinatorics';
diff --git a/challenge-085/polettix/perl/cpanfile.snapshot b/challenge-085/polettix/perl/cpanfile.snapshot
new file mode 100644
index 0000000000..4e08a1bd79
--- /dev/null
+++ b/challenge-085/polettix/perl/cpanfile.snapshot
@@ -0,0 +1,8 @@
+# carton snapshot format: version 1.0
+DISTRIBUTIONS
+  Math-Combinatorics-0.09
+    pathname: A/AL/ALLENDAY/Math-Combinatorics-0.09.tar.gz
+    provides:
+      Math::Combinatorics 0.09
+    requirements:
+      ExtUtils::MakeMaker 0