Merge pull request #5237 from wlmb/challenges

Challenges

3 files changed, 45 insertions, 0 deletions

diff --git a/challenge-139/wlmb/blog.txt b/challenge-139/wlmb/blog.txt
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+https://wlmb.github.io/2021/11/16/PWC139/
diff --git a/challenge-139/wlmb/perl/ch-1.pl b/challenge-139/wlmb/perl/ch-1.pl
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+#!/usr/bin/env perl
+# Perl weekly challenge 139
+# Task 1: JortSort
+#
+# See https://wlmb.github.io/2021/11/16/PWC139/#task-1-jortsort
+use v5.12;
+use warnings;
+use List::Util qw(none);
+say "Input: (", (join " ",@ARGV), ")";
+my $x; # previous element
+my $y=shift @ARGV; # current element
+say "Output: ", (none {($x,$y)=($y,$_); $x>$y}@ARGV)?1:0;
diff --git a/challenge-139/wlmb/perl/ch-2.pl b/challenge-139/wlmb/perl/ch-2.pl
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+#!/usr/bin/env perl
+# Perl weekly challenge 139
+# Task 2: Long Primes
+#
+# See https://wlmb.github.io/2021/11/16/PWC139/#task-2-long-primes
+use v5.12;
+use warnings;
+use bignum;
+use Math::Prime::Util qw(next_prime);
+use List::Util qw(first);
+use Text::Wrap qw(wrap $columns $break);
+$columns=62;
+$break=qr/\s|_/;
+my $max_count=shift @ARGV//5; # get number of long primes from command line
+my $prime=2; #current prime (will skip '2')
+my $count=0;
+my @lines;
+while($count<$max_count){
+    $prime=next_prime($prime);
+    my $length=$prime-1; # expected length of large cycle
+    Math::BigFloat->accuracy(3.5*$length); # allow 3+ repetitions
+    my @groups= grep {$_} split /(\d{$length})/, 1./$prime; # groups of digits
+    pop @groups; # throw away last (guard) repetition (posibly inexact)
+     ++$count, push @lines,
+                    "$count-th long prime is $prime",
+		    "       as 1/$prime = " . shift(@groups) . join "_", @groups,"..."
+        if (first # if cycle doesn't stop early
+           {my $x=10**$_%$prime; $x==1||$x==0}
+           (1..$prime-1))
+	   == $prime-1
+}
+say wrap("", "                  _", $_) for @lines;