Merge pull request #5608 from polettix/polettix/pwc150

Add polettix's solution to challenge-150

6 files changed, 126 insertions, 0 deletions

diff --git a/challenge-150/polettix/blog.txt b/challenge-150/polettix/blog.txt
new file mode 100644
index 0000000000..fd01d159e1
--- /dev/null
+++ b/challenge-150/polettix/blog.txt
@@ -0,0 +1 @@
+https://github.polettix.it/ETOOBUSY/2022/02/02/pwc150-fibonacci-words/
diff --git a/challenge-150/polettix/blog1.txt b/challenge-150/polettix/blog1.txt
new file mode 100644
index 0000000000..6c54896efa
--- /dev/null
+++ b/challenge-150/polettix/blog1.txt
@@ -0,0 +1 @@
+https://github.polettix.it/ETOOBUSY/2022/02/03/pwc150-square-free-integer/
diff --git a/challenge-150/polettix/perl/ch-1.pl b/challenge-150/polettix/perl/ch-1.pl
new file mode 100644
index 0000000000..2540b80cc4
--- /dev/null
+++ b/challenge-150/polettix/perl/ch-1.pl
@@ -0,0 +1,31 @@
+#!/usr/bin/env perl
+use 5.024;
+use warnings;
+use English qw< -no_match_vars >;
+use experimental qw< postderef signatures >;
+no warnings qw< experimental::postderef experimental::signatures >;
+
+say "Fibonacci Words:\n";
+my $it = fibonacci_words_iterator(@ARGV);
+while ('necessary') {
+   my $item = $it->();
+   say "'$item'";
+   if (length $item >= 51) {
+      my $digit = substr $item, 50, 1;
+      say "\nThe 51st digit in the first term having at least 51 digits '$item' is $digit.";
+      last;
+   }
+}
+
+sub fibonacci_words_iterator ($f0, $f1) {
+   my @cache = ('', '', $f0, $f1);
+   my $backlog = 2;
+   return sub {
+      if (! $backlog) {
+         ($f0, $f1) = ($f1, $f0 . $f1);
+         return $f1;
+      }
+      --$backlog;
+      return $backlog ? $f0 : $f1;
+   };
+}
diff --git a/challenge-150/polettix/perl/ch-2.pl b/challenge-150/polettix/perl/ch-2.pl
new file mode 100644
index 0000000000..02c037e5f4
--- /dev/null
+++ b/challenge-150/polettix/perl/ch-2.pl
@@ -0,0 +1,32 @@
+#!/usr/bin/env perl
+use 5.024;
+use warnings;
+use English qw< -no_match_vars >;
+use experimental qw< postderef signatures >;
+no warnings qw< experimental::postderef experimental::signatures >;
+
+if (@ARGV > 1) { 
+   say $_, ' ', (is_square_free($_) ? 'is' : 'is not'), ' square free'
+      for @ARGV;
+}
+else {
+   my $limit = shift // 500;
+   my @list = grep { is_square_free($_) } 1 .. $limit;
+   while (@list) {
+      print join ', ', splice @list, 0, 20;
+      say @list ? ',' : '';
+   }
+}
+
+sub is_square_free ($N) {
+   return unless $N % 4;
+   my $divisor = 3;
+   while ($N > $divisor) {
+      if ($N % $divisor == 0) {
+         $N /= $divisor;
+         return unless $N % $divisor;
+      }
+      $divisor += 2; # go through odd candidates only
+   }
+   return 1;
+}
diff --git a/challenge-150/polettix/raku/ch-1.raku b/challenge-150/polettix/raku/ch-1.raku
new file mode 100644
index 0000000000..f37cf06124
--- /dev/null
+++ b/challenge-150/polettix/raku/ch-1.raku
@@ -0,0 +1,33 @@
+#!/usr/bin/env raku
+use v6;
+
+class FibonacciWords { ... };
+
+sub MAIN (Int:D $a, Int:D $b where $b.Str.chars == $a.Str.chars) {
+   my $it = FibonacciWords.new($a, $b);
+   put "Fibonacci Words\n";
+   loop {
+      my $item = $it.next();
+      put "'$item'";
+      if $item.chars >= 51 {
+         my $digit = $item.substr(50, 1);
+         put "\nThe 51st digit in the first term having at least 51 digits '$item' is $digit.";
+         last;
+      }
+   }
+}
+
+class FibonacciWords {
+   has $!f0 is built;
+   has $!f1 is built;
+   has $!backlog = 2;
+   method new (Str() $f0, Str() $f1) { self.bless(:$f0, :$f1) }
+   method next () {
+      if ! $!backlog {
+         ($!f0, $!f1) = ($!f1, $!f0 ~ $!f1);
+         return $!f1;
+      }
+      --$!backlog;
+      return $!backlog ?? $!f0 !! $!f1;
+   }
+}
diff --git a/challenge-150/polettix/raku/ch-2.raku b/challenge-150/polettix/raku/ch-2.raku
new file mode 100644
index 0000000000..35a29749b0
--- /dev/null
+++ b/challenge-150/polettix/raku/ch-2.raku
@@ -0,0 +1,28 @@
+#!/usr/bin/env raku
+use v6;
+
+multi sub MAIN (Int $limit = 500) {
+   my @list = (1 .. $limit).grep({is-square-free($_)});
+   while @list {
+      @list.splice(0, 20).join(', ').print;
+      put @list ?? ',' !! '';
+   }
+}
+
+multi sub MAIN (*@args) {
+   put $_, ' ', (is-square-free($_) ?? 'is' !! 'is not'), ' square free'
+      for @args;
+}
+
+sub is-square-free ($N is copy) {
+   return False if $N %% 4;
+   my $divisor = 3;
+   while $N > $divisor {
+      if $N %% $divisor == 0 {
+         $N = ($N / $divisor).Int;
+         return False if $N %% $divisor;
+      }
+      $divisor += 2; # go through odd candidates only
+   }
+   return True;
+}