Task 1 & 2

2 files changed, 131 insertions, 0 deletions

diff --git a/challenge-102/perlboy1967/perl/ch-1.pl b/challenge-102/perlboy1967/perl/ch-1.pl
new file mode 100755
index 0000000000..1aad958dfa
--- /dev/null
+++ b/challenge-102/perlboy1967/perl/ch-1.pl
@@ -0,0 +1,97 @@
+#!/usr/bin/perl
+
+# Perl Weekly Challenge - 102
+# - https://perlweeklychallenge.org/blog/perl-weekly-challenge-102/#TASK1
+#
+# Task 1 - Rare Numbers
+#
+# Author: Niels 'PerlBoy' van Dijke
+#
+# Note: This is the first time I use MCE.
+# Possibly I use it not optimally ;-)
+
+use v5.16;
+use strict;
+use warnings;
+
+use MCE;
+use MCE::Util;
+
+use POSIX qw(ceil);
+use Time::HiRes qw(gettimeofday tv_interval);
+use List::Util qw(min);
+
+@ARGV = (9)
+  unless (scalar @ARGV);
+
+my $N = shift @ARGV;
+
+die "Please provide integer number >= 1"
+  unless ($N =~ m#^\d+$# and $N >= 1);
+
+my %rep = (
+  1 => 2,
+  3 => 4,
+  5 => 6,
+  7 => 8,
+  9 => 20,
+);
+
+my ($r0,$r1) = (1,1);
+
+my $t0 = [gettimeofday];
+
+my @results;
+
+my $mce = MCE->new(
+     chunk_size => 10_000,
+     max_workers => MCE::Util::get_ncpu(),
+     user_func => sub {
+       my ($mce, $chunk_ref, $chunk_id) = @_;
+
+       foreach (@$chunk_ref) {
+         if (isRare($_)) {
+           my $elapsed = tv_interval ($t0);
+           printf "%6.3f rare: %d\n", $elapsed, $_;
+         }
+       }
+     }
+);
+
+do {
+  $r0++;
+
+  # Small optimization
+  # (skip all numbers which start with an odd number)
+  my $d = substr($r0,0,1);
+  if (exists $rep{$d}) {
+    substr($r0,0,1,$rep{$d});
+  }
+
+  # Create dynamic chunks with a maximum of 1M
+  # (to keep memory utilisation in control)
+  my $step = min(1_000_000, 10**ceil(log($r0)/log(10)) - 1 - $r0);
+  $mce->process([ $r0 .. $r0+$step ]);
+  $r0 += $step;
+
+} until ($r0 > 10**$N);
+
+
+sub isRare {
+  my $r1 = int(reverse($_[0]));
+
+  # Palindrome number cannot be rare number
+  return 0 if ($r1 == $_[0]);
+
+  my $d = $_[0] - $r1;
+  return 0 if ($d <= 0);
+  my $sqrtD = sqrt($d);
+  return 0 if ($sqrtD != int($sqrtD));
+
+  my $s = $_[0] + $r1;
+  my $sqrtS = sqrt($s);
+  return 0 if ($sqrtS != int($sqrtS));
+
+  return 1;
+}
+
diff --git a/challenge-102/perlboy1967/perl/ch-2.pl b/challenge-102/perlboy1967/perl/ch-2.pl
new file mode 100755
index 0000000000..4689fa80a9
--- /dev/null
+++ b/challenge-102/perlboy1967/perl/ch-2.pl
@@ -0,0 +1,34 @@
+#!/usr/bin/perl
+
+# Perl Weekly Challenge - 102
+# - https://perlweeklychallenge.org/blog/perl-weekly-challenge-102/#TASK2
+#
+# Task 2 - Hash-counting String
+#
+# Author: Niels 'PerlBoy' van Dijke
+
+use v5.16;
+use strict;
+use warnings;
+
+@ARGV = (<>)
+  unless (scalar @ARGV);
+
+foreach my $n (@ARGV) {
+  printf "hashCountingString(%d) = '%s'\n",
+         $n, hashCountingString($n);
+}
+
+
+sub hashCountingString {
+  my ($n) = @_;
+
+  my $r = '';
+
+  while ($n > 0) {
+    $r = ($n > 1 ? $n.'#'.$r : '#'.$r);
+    $n -= length($n) + 1;
+  }
+
+  return $r;
+}