From 8c763f1bd7e9fb4c7ba1a80dc339ffbd9a23b333 Mon Sep 17 00:00:00 2001
From: Adam Russell <ac.russell@live.com>
Date: Sun, 3 Dec 2023 20:44:39 -0500
Subject: removed old .gitignore files

---
 challenge-243/adam-russell/.gitignore | 3 ---
 challenge-244/adam-russell/.gitignore | 3 ---
 2 files changed, 6 deletions(-)
 delete mode 100644 challenge-243/adam-russell/.gitignore
 delete mode 100644 challenge-244/adam-russell/.gitignore

diff --git a/challenge-243/adam-russell/.gitignore b/challenge-243/adam-russell/.gitignore
deleted file mode 100644
index d4e9a94d5e..0000000000
--- a/challenge-243/adam-russell/.gitignore
+++ /dev/null
@@ -1,3 +0,0 @@
-*.bbprojectd
-.RData
-.Rhistory
diff --git a/challenge-244/adam-russell/.gitignore b/challenge-244/adam-russell/.gitignore
deleted file mode 100644
index d4e9a94d5e..0000000000
--- a/challenge-244/adam-russell/.gitignore
+++ /dev/null
@@ -1,3 +0,0 @@
-*.bbprojectd
-.RData
-.Rhistory
-- 
cgit 


From b83ae6bf5ef619abe85510b5810b8b7e84a5224f Mon Sep 17 00:00:00 2001
From: Bob Lied <boblied+github@gmail.com>
Date: Tue, 5 Dec 2023 16:30:41 -0600
Subject: Make random number picks unique

---
 challenge-246/bob-lied/perl/ch-1.pl | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/challenge-246/bob-lied/perl/ch-1.pl b/challenge-246/bob-lied/perl/ch-1.pl
index 394f4db426..07c2d59d52 100644
--- a/challenge-246/bob-lied/perl/ch-1.pl
+++ b/challenge-246/bob-lied/perl/ch-1.pl
@@ -10,4 +10,12 @@
 #=============================================================================
 
 use feature qw/say/;
-say for sort { $a <=> $b} map { int(rand(49)) + 1 } 1..6;
+
+# Choose six numbers without repeats
+my %seen;
+while ( scalar(%seen) < 6 )
+{
+    $seen{ int(rand(49)) + 1 } = 1;
+}
+
+say for sort { $a <=> $b } keys %seen;
-- 
cgit 


From 8c83d2379bec6a8df0291d5d2831ebbfe3051e41 Mon Sep 17 00:00:00 2001
From: Bob Lied <boblied+github@gmail.com>
Date: Tue, 5 Dec 2023 16:45:33 -0600
Subject: Correct size of hash

---
 challenge-246/bob-lied/perl/ch-1.pl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/challenge-246/bob-lied/perl/ch-1.pl b/challenge-246/bob-lied/perl/ch-1.pl
index 07c2d59d52..56b1ae4e26 100644
--- a/challenge-246/bob-lied/perl/ch-1.pl
+++ b/challenge-246/bob-lied/perl/ch-1.pl
@@ -13,7 +13,7 @@ use feature qw/say/;
 
 # Choose six numbers without repeats
 my %seen;
-while ( scalar(%seen) < 6 )
+while ( scalar(keys %seen) < 6 )
 {
     $seen{ int(rand(49)) + 1 } = 1;
 }
-- 
cgit 


From 86b40a444f6ad097e863471eb41738fdc304e255 Mon Sep 17 00:00:00 2001
From: Mark <53903062+andemark@users.noreply.github.com>
Date: Mon, 11 Dec 2023 05:32:00 +0000
Subject: Challenge 247 Solutions (Raku)

---
 challenge-247/mark-anderson/raku/ch-1.raku | 36 ++++++++++++++++++++++++++++++
 challenge-247/mark-anderson/raku/ch-2.raku | 10 +++++++++
 2 files changed, 46 insertions(+)
 create mode 100644 challenge-247/mark-anderson/raku/ch-1.raku
 create mode 100644 challenge-247/mark-anderson/raku/ch-2.raku

diff --git a/challenge-247/mark-anderson/raku/ch-1.raku b/challenge-247/mark-anderson/raku/ch-1.raku
new file mode 100644
index 0000000000..92ae775140
--- /dev/null
+++ b/challenge-247/mark-anderson/raku/ch-1.raku
@@ -0,0 +1,36 @@
+#!/usr/bin/env raku
+use Test;
+
+is-deeply secret-santa(["Mr. Wall", "Mrs. Wall", "Mr. Anwar",
+                        "Mrs. Anwar", "Mr. Conway", "Mr. Cross"]),
+          {
+              "Mrs. Anwar" => "Mr. Conway", 
+              "Mr. Conway" => "Mr. Cross", 
+              "Mr. Cross"  => "Mrs. Wall", 
+              "Mrs. Wall"  => "Mr. Anwar", 
+              "Mr. Anwar"  => "Mr. Wall", 
+              "Mr. Wall"   => "Mrs. Anwar"
+          }
+
+is-deeply secret-santa(["Mr. Wall", "Mrs. Wall", "Mr. Anwar"]),
+          {
+              "Mr. Anwar" => "Mrs. Wall", 
+              "Mr. Wall"  => "Mr. Anwar", 
+              "Mrs. Wall" => "Mr. Wall"
+          }
+
+sub secret-santa(@names)
+{
+    my %surname = @names.classify({ .words[1] });
+
+    my @r = gather given %surname.values.sort.Array
+    {
+        while .elems
+        {
+            take .head.pop;
+            .head ?? $_ .= rotate !! .splice(0,1)
+        }
+    }
+
+    @r.push(@r.head).rotor(2 => -1).map({ .pairup.head }).Hash
+}
diff --git a/challenge-247/mark-anderson/raku/ch-2.raku b/challenge-247/mark-anderson/raku/ch-2.raku
new file mode 100644
index 0000000000..532186b18e
--- /dev/null
+++ b/challenge-247/mark-anderson/raku/ch-2.raku
@@ -0,0 +1,10 @@
+#!/usr/bin/env raku
+use Test;
+
+is most-freq-pair("abcdbca"),           "bc";
+is most-freq-pair("cdeabeabfcdfabgcd"), "ab";
+
+sub most-freq-pair($str)
+{
+    ($str ~~ m:ov/../)>>.Str.Bag.maxpairs.sort.head.key
+}
-- 
cgit 


From e32e843f21a9d6995c974980cc36a180ab1ddd32 Mon Sep 17 00:00:00 2001
From: Mark <53903062+andemark@users.noreply.github.com>
Date: Mon, 11 Dec 2023 05:42:53 +0000
Subject: Challenge 247 Solutions (Raku)

---
 challenge-247/mark-anderson/raku/ch-1.raku | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/challenge-247/mark-anderson/raku/ch-1.raku b/challenge-247/mark-anderson/raku/ch-1.raku
index 92ae775140..a3ae0d336a 100644
--- a/challenge-247/mark-anderson/raku/ch-1.raku
+++ b/challenge-247/mark-anderson/raku/ch-1.raku
@@ -28,7 +28,7 @@ sub secret-santa(@names)
         while .elems
         {
             take .head.pop;
-            .head ?? $_ .= rotate !! .splice(0,1)
+            .head ?? $_ .= rotate !! .shift
         }
     }
 
-- 
cgit 


From c206e58869e6eca3d969e6af32074facce5a5d4e Mon Sep 17 00:00:00 2001
From: Thomas Köhler <jean-luc@picard.franken.de>
Date: Mon, 11 Dec 2023 10:18:13 +0100
Subject: Add solution 247
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: Thomas Köhler <jean-luc@picard.franken.de>
---
 challenge-247/jeanluc2020/blog-1.txt   |   1 +
 challenge-247/jeanluc2020/blog-2.txt   |   1 +
 challenge-247/jeanluc2020/perl/ch-1.pl | 109 +++++++++++++++++++++++++++++++++
 challenge-247/jeanluc2020/perl/ch-2.pl |  55 +++++++++++++++++
 4 files changed, 166 insertions(+)
 create mode 100644 challenge-247/jeanluc2020/blog-1.txt
 create mode 100644 challenge-247/jeanluc2020/blog-2.txt
 create mode 100755 challenge-247/jeanluc2020/perl/ch-1.pl
 create mode 100755 challenge-247/jeanluc2020/perl/ch-2.pl

diff --git a/challenge-247/jeanluc2020/blog-1.txt b/challenge-247/jeanluc2020/blog-1.txt
new file mode 100644
index 0000000000..a1594d1d94
--- /dev/null
+++ b/challenge-247/jeanluc2020/blog-1.txt
@@ -0,0 +1 @@
+http://gott-gehabt.de/800_wer_wir_sind/thomas/Homepage/Computer/perl/theweeklychallenge-247-1.html
diff --git a/challenge-247/jeanluc2020/blog-2.txt b/challenge-247/jeanluc2020/blog-2.txt
new file mode 100644
index 0000000000..dcd5376ede
--- /dev/null
+++ b/challenge-247/jeanluc2020/blog-2.txt
@@ -0,0 +1 @@
+http://gott-gehabt.de/800_wer_wir_sind/thomas/Homepage/Computer/perl/theweeklychallenge-247-2.html
diff --git a/challenge-247/jeanluc2020/perl/ch-1.pl b/challenge-247/jeanluc2020/perl/ch-1.pl
new file mode 100755
index 0000000000..28a758d523
--- /dev/null
+++ b/challenge-247/jeanluc2020/perl/ch-1.pl
@@ -0,0 +1,109 @@
+#!/usr/bin/perl
+# https://theweeklychallenge.org/blog/perl-weekly-challenge-247/#TASK1
+#
+# Task 1: Secret Santa
+# ====================
+#
+# Task 1: Secret Santa
+# Submitted by: Andreas Voegele
+#
+# Secret Santa is a Christmas tradition in which members of a group are
+# randomly assigned a person to whom they give a gift.
+#
+# You are given a list of names. Write a script that tries to team persons from
+# different families.
+#
+## Example 1
+##
+## The givers are randomly chosen but don't share family names with the receivers.
+##
+## Input: @names = ('Mr. Wall',
+##                  'Mrs. Wall',
+##                  'Mr. Anwar',
+##                  'Mrs. Anwar',
+##                  'Mr. Conway',
+##                  'Mr. Cross',
+##                  );
+##
+## Output:
+##
+##     Mr. Conway -> Mr. Wall
+##     Mr. Anwar -> Mrs. Wall
+##     Mrs. Wall -> Mr. Anwar
+##     Mr. Cross -> Mrs. Anwar
+##     Mr. Wall -> Mr. Conway
+##     Mrs. Anwar -> Mr. Cross
+#
+## Example 2
+##
+## One gift is given to a family member.
+##
+## Input: @names = ('Mr. Wall',
+##                  'Mrs. Wall',
+##                  'Mr. Anwar',
+##                  );
+##
+## Output:
+##
+##     Mr. Anwar -> Mr. Wall
+##     Mr. Wall -> Mrs. Wall
+##     Mrs. Wall -> Mr. Anwar
+#
+############################################################
+##
+## discussion
+##
+############################################################
+#
+# We create all possible permutations for the input. Then we
+# eliminate all of those that have two people of the same family
+# next to each other. Then we select one of the remaining
+# permutations randomly.
+
+use strict;
+use warnings;
+use Data::Dumper;
+use Algorithm::Permute;
+
+secret_santa('Mr. Wall', 'Mrs. Wall', 'Mr. Anwar', 'Mrs. Anwar', 'Mr. Conway', 'Mr. Cross');
+secret_santa('Mr. Wall', 'Mrs. Wall', 'Mr. Anwar');
+
+sub secret_santa {
+   my @names = @_;
+   my @permutations = ();
+   my $p_iterator = Algorithm::Permute->new ( \@names );
+   my @current_permutation;
+   while (my @perm = $p_iterator->next) {
+      @current_permutation = @perm;
+      if(valid(@perm)) {
+         push @permutations, [@perm];
+      }
+   }
+   print Dumper \@permutations;
+   unless(@permutations) {
+      push @permutations, [ @current_permutation ];
+   }
+   my $which = int(rand(scalar(@permutations)));
+   my $permutation = $permutations[$which];
+   my $last = shift @$permutation;
+   push @$permutation, $last;
+   foreach my $who (@$permutation) {
+      print "$last -> $who\n";
+      $last = $who;
+   }
+}
+
+sub valid {
+   my @perm = @_;
+   my $last = shift @perm;
+   push @perm, $last;
+   foreach my $name (@perm) {
+      my $family_last = $last;
+      $family_last =~ s/.* //;
+      my $family_this = $name;
+      $family_this =~ s/.* //;
+      return 0 if $family_last eq $family_this;
+      $last = $name;
+   }
+   return 1;
+}
diff --git a/challenge-247/jeanluc2020/perl/ch-2.pl b/challenge-247/jeanluc2020/perl/ch-2.pl
new file mode 100755
index 0000000000..e697827a3c
--- /dev/null
+++ b/challenge-247/jeanluc2020/perl/ch-2.pl
@@ -0,0 +1,55 @@
+#!/usr/bin/perl
+# https://theweeklychallenge.org/blog/perl-weekly-challenge-247/#TASK2
+#
+# Task 2: Most Frequent Letter Pair
+# =================================
+#
+# You are given a string S of lower case letters 'a'..'z'.
+#
+# Write a script that finds the pair of consecutive letters in S that appears
+# most frequently. If there is more than one such pair, chose the one that is
+# the lexicographically first.
+#
+## Example 1
+##
+## Input: $s = 'abcdbca'
+## Output: 'bc'
+##
+## 'bc' appears twice in `$s`
+#
+## Example 2
+##
+## Input: $s = 'cdeabeabfcdfabgcd'
+## Output: 'ab'
+##
+## 'ab' and 'cd' both appear three times in $s and 'ab' is lexicographically
+## smaller than 'cd'.
+#
+############################################################
+##
+## discussion
+##
+############################################################
+#
+# Create a map with all substrings as keys and their frequency as value,
+# then sort by frequency descending and then by key ascending and return
+# the first element of the sorted list
+
+use strict;
+use warnings;
+
+most_frequent_letter_pair('abcdbca');
+most_frequent_letter_pair('cdeabeabfcdfabgcd');
+
+sub most_frequent_letter_pair {
+   my $s = shift;
+   print "Input: $s\n";
+   my @letters = split //, $s;
+   my $map = {};
+   foreach my $i (0..$#letters-1) {
+      my $new = $letters[$i] . $letters[$i+1];
+      $map->{$new}++;
+   }
+   my @sorted = sort { $map->{$b} <=> $map->{$a} || $a cmp $b } keys %$map;
+   print "Output: $sorted[0]\n";
+}
-- 
cgit 


From 56ed453655d987a9506a5f559e604bd211e79edf Mon Sep 17 00:00:00 2001
From: Roger Bell_West <roger@firedrake.org>
Date: Mon, 11 Dec 2023 10:21:42 +0000
Subject: RogerBW blog post for challenge no. 246

---
 challenge-246/roger-bell-west/blog.txt | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 challenge-246/roger-bell-west/blog.txt

diff --git a/challenge-246/roger-bell-west/blog.txt b/challenge-246/roger-bell-west/blog.txt
new file mode 100644
index 0000000000..0f5c0a56cb
--- /dev/null
+++ b/challenge-246/roger-bell-west/blog.txt
@@ -0,0 +1 @@
+https://blog.firedrake.org/archive/2023/12/The_Weekly_Challenge_246__Linear_49.html
-- 
cgit 


From f52eeb84259418b208d965ac7f97819de86bd8de Mon Sep 17 00:00:00 2001
From: Bob Lied <boblied+github@gmail.com>
Date: Mon, 11 Dec 2023 08:50:57 -0600
Subject: PWC 24 task 1 done

---
 challenge-247/bob-lied/README       |   6 +-
 challenge-247/bob-lied/perl/ch-1.pl | 111 ++++++++++++++++++++++++++++++++++++
 2 files changed, 114 insertions(+), 3 deletions(-)
 create mode 100644 challenge-247/bob-lied/perl/ch-1.pl

diff --git a/challenge-247/bob-lied/README b/challenge-247/bob-lied/README
index 2c14618b4f..ddf6e99243 100644
--- a/challenge-247/bob-lied/README
+++ b/challenge-247/bob-lied/README
@@ -1,4 +1,4 @@
-Solutions to weekly challenge 246 by Bob Lied
+Solutions to weekly challenge 247 by Bob Lied
 
-https://perlweeklychallenge.org/blog/perl-weekly-challenge-246/
-https://github.com/boblied/perlweeklychallenge-club/tree/master/challenge-246/bob-lied
+https://perlweeklychallenge.org/blog/perl-weekly-challenge-247/
+https://github.com/boblied/perlweeklychallenge-club/tree/master/challenge-247/bob-lied
diff --git a/challenge-247/bob-lied/perl/ch-1.pl b/challenge-247/bob-lied/perl/ch-1.pl
new file mode 100644
index 0000000000..e201bff1d6
--- /dev/null
+++ b/challenge-247/bob-lied/perl/ch-1.pl
@@ -0,0 +1,111 @@
+#!/usr/bin/env perl
+# vim:set ts=4 sw=4 sts=4 et ai wm=0 nu:
+#=============================================================================
+# Copyright (c) 2023, Bob Lied
+#=============================================================================
+# part1.pl Perl Weekly Challenge 247 Task 1 Secret Santa
+#=============================================================================
+# Secret Santa is a Christmas tradition in which members of a group are
+# randomly assigned a person to whom they give a gift.
+# You are given a list of names. Write a script that tries to team persons
+# from different families. The givers are randomly chosen but don't share
+# family names with the receivers.
+# Example 1 Input: @names = (
+#       'Mr. Wall', 'Mrs. Wall', 'Mr. Anwar', 'Mrs. Anwar',
+#       'Mr. Conway', 'Mr. Cross',);
+#           Output: Mr. Conway -> Mr. Wall
+#                   Mr. Anwar -> Mrs. Wall
+#                   Mrs. Wall -> Mr. Anwar
+#                   Mr. Cross -> Mrs. Anwar
+#                   Mr. Wall -> Mr. Conway
+#                   Mrs. Anwar -> Mr. Cross
+# Example 2 One gift is given to a family member.
+#           Input: @names = ('Mr. Wall', 'Mrs. Wall', 'Mr. Anwar',);
+#           Output: Mr. Anwar -> Mr. Wall
+#                   Mr. Wall -> Mrs. Wall
+#                   Mrs. Wall -> Mr. Anwar
+#=============================================================================
+
+use v5.38;
+use builtin qw/true false/; no warnings "experimental::builtin";
+
+use List::Util qw/all sample/;
+
+use Getopt::Long;
+my $Verbose = 0;
+my $DoTest  = 0;
+
+GetOptions("test" => \$DoTest, "verbose" => \$Verbose);
+exit(!runTest()) if $DoTest;
+
+my $picks = secretSanta(@ARGV);
+say "$_ -> $picks->{$_}" for
+    sort { surname($a) cmp surname($b) || $a cmp $b } keys %$picks;
+
+sub secretSanta(@names)
+{
+    return {} if ( @names < 2 );
+    my %picks;
+PICKEM:
+    my %available = map { $_ => true } @names;
+    for my $name (@names)
+    {
+        my @choices = grep { surname($_) ne surname($name) } keys %available;
+        if ( @choices == 0 )
+        {
+            # Must pick within family, but not self
+            @choices = grep { $_ ne $name } keys %available;
+
+            # If we got down to one person picking themselves, try again
+            if ( @choices == 0 )
+            {
+                warn "Self-pick detected, retry";
+                %picks = ();
+                goto PICKEM;
+            }
+        }
+
+        my $recipient = sample 1, @choices;
+        delete $available{$recipient}; 
+
+        $picks{$name} = $recipient;
+    }
+    return \%picks
+}
+
+sub surname($name) { (split(" ", $name))[-1]; }
+
+sub runTest
+{
+    use Test2::V0;
+
+    my @names; my $picks;
+    @names = ( 'Mr. Wall', 'Mrs. Wall', 'Mr. Anwar', 'Mrs. Anwar',
+               'Mr. Conway', 'Mr. Cross',);
+    my $expect = {
+                'Mr. Anwar'  => 'Mrs. Wall' ,
+                'Mr. Conway' => 'Mr. Wall'  ,
+                'Mr. Cross'  => 'Mrs. Anwar',
+                'Mr. Wall'   => 'Mr. Conway',
+                'Mrs. Anwar' => 'Mr. Cross' ,
+                'Mrs. Wall'  => 'Mr. Anwar' ,
+              };
+    $picks = secretSanta(@names);
+
+    is( scalar(keys %$picks), scalar(@names), "Enough picks");
+    ok( (all { exists $picks->{$_} } @names), "All givers have a recipient");
+    is( [sort @names], [sort values %$picks], "Every one gets a gift");
+    ok( (all { $_ ne $picks->{$_}  } @names), "No one picks themselves");
+    ok( (all { surname($_) ne surname($picks->{$_}) } @names ), "All picks outside family");
+
+    @names = ( 'Mr. Wall', 'Mrs. Wall', 'Mr. Anwar' );
+    $picks = secretSanta(@names);
+
+    is( scalar(keys %$picks), scalar(@names), "Enough picks");
+    ok( (all { exists $picks->{$_} } @names), "All givers have a recipient");
+    is( [sort @names], [sort values %$picks], "Every one gets a gift");
+    ok( (all { $_ ne $picks->{$_}  } @names), "No one picks themselves");
+    is( surname($picks->{'Mr. Anwar'}), 'Wall', "Anwar picks a Wall");
+
+    done_testing;
+}
-- 
cgit 


From cf780136eaea2075524c500d5989bcf5403d8c9b Mon Sep 17 00:00:00 2001
From: Bob Lied <boblied+github@gmail.com>
Date: Mon, 11 Dec 2023 08:58:41 -0600
Subject: PWC 247 Task 2 complete

---
 challenge-247/bob-lied/perl/ch-2.pl | 44 +++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)
 create mode 100644 challenge-247/bob-lied/perl/ch-2.pl

diff --git a/challenge-247/bob-lied/perl/ch-2.pl b/challenge-247/bob-lied/perl/ch-2.pl
new file mode 100644
index 0000000000..07735608c3
--- /dev/null
+++ b/challenge-247/bob-lied/perl/ch-2.pl
@@ -0,0 +1,44 @@
+#!/usr/bin/env perl
+# vim:set ts=4 sw=4 sts=4 et ai wm=0 nu:
+#=============================================================================
+# ch-2.pl Perl Weekly Challenge 247 Task 2 Most Frequent Letter Pair
+#=============================================================================
+# You are given a string S of lower case letters 'a'..'z'.
+# Write a script that finds the pair of consecutive letters in S that
+# appears most frequently. If there is more than one such pair, choose
+# the one that is the lexicographically first.
+# Example 1 Input: $s = 'abcdbca'
+#           Output: 'bc'  ('bc' appears twice in `$s`)
+# Example 2 Input: $s = 'cdeabeabfcdfabgcd'
+#           Output: 'ab'
+#=============================================================================
+# Copyright (c) 2023, Bob Lied
+#=============================================================================
+
+use v5.38;
+
+use builtin qw/true false/; no warnings "experimental::builtin";
+
+use Getopt::Long;
+my $Verbose = 0;
+my $DoTest  = 0;
+
+GetOptions("test" => \$DoTest, "verbose" => \$Verbose);
+exit(!runTest()) if $DoTest;
+
+sub mflp($s)
+{
+    my %freq;
+    $freq{$_}++ for map { substr($s, $_, 2) } 0 .. (length($s)-2);
+    return (sort { $freq{$b} <=> $freq{$a} || $a cmp $b } keys %freq)[0];
+}
+
+sub runTest
+{
+    use Test2::V0;
+
+    is( mflp("abcdbca"),           'bc', "Example 1");
+    is( mflp("cdeabeabfcdfabgcd"), 'ab', "Example 2");
+
+    done_testing;
+}
-- 
cgit 


From 321ee201cc101575264dd4ac8a8cd70bd96e31a6 Mon Sep 17 00:00:00 2001
From: Niels van Dijke <perlboy@cpan.org>
Date: Mon, 11 Dec 2023 15:17:39 +0000
Subject: w247 - Task 1 & 2

---
 challenge-247/perlboy1967/perl/ch1.pl | 82 +++++++++++++++++++++++++++++++++++
 challenge-247/perlboy1967/perl/ch2.pl | 49 +++++++++++++++++++++
 2 files changed, 131 insertions(+)
 create mode 100755 challenge-247/perlboy1967/perl/ch1.pl
 create mode 100755 challenge-247/perlboy1967/perl/ch2.pl

diff --git a/challenge-247/perlboy1967/perl/ch1.pl b/challenge-247/perlboy1967/perl/ch1.pl
new file mode 100755
index 0000000000..d41ed73cd6
--- /dev/null
+++ b/challenge-247/perlboy1967/perl/ch1.pl
@@ -0,0 +1,82 @@
+#!/bin/perl
+
+=pod
+
+The Weekly Challenge - 247
+- https://theweeklychallenge.org/blog/perl-weekly-challenge-247
+
+Author: Niels 'PerlBoy' van Dijke
+
+Task 1: Secret Santa
+Submitted by: Andreas Voegele
+
+Secret Santa is a Christmas tradition in which members of a group are randomly
+assigned a person to whom they give a gift.
+
+You are given a list of names. Write a script that tries to team persons from
+different families.
+
+=cut
+
+use v5.32;
+use common::sense;
+use feature qw(signatures);
+
+use Test2::V0 -srand => 247;
+
+use List::Util qw(shuffle);
+
+sub nameSort {
+  my @a = split(/\s+/,$a);
+  my @b = split(/\s+/,$b);
+  return $a[1] cmp $b[1] || $a[0] cmp $b[0];
+}
+
+sub secretSanta(@names1) {
+  my @names2 = shuffle @names1;
+  my @assignments;
+
+  while (my $name1 = shift(@names1)) {
+    my ($lastname1) = $name1 =~ m#(\S+)$#;
+    if ($#names2 > 1) {
+      while ($names2[0] =~ m#(\S+)$# and $lastname1 eq $1) {
+        push(@names2,shift @names2);
+      }
+    }
+    push(@assignments,sprintf("%s -> %s",$name1,shift @names2));
+  }     
+
+  [sort nameSort @assignments]; 
+}
+
+is(secretSanta(
+     'Mr. Wall',
+     'Mrs. Wall',
+     'Mr. Anwar',
+     'Mrs. Anwar',
+     'Mr. Conway',
+     'Mr. Cross',
+   ), 
+   [
+     'Mr. Anwar -> Mr. Cross',
+     'Mrs. Anwar -> Mrs. Wall',
+     'Mr. Conway -> Mr. Wall',
+     'Mr. Cross -> Mrs. Anwar',
+     'Mr. Wall -> Mr. Conway',
+     'Mrs. Wall -> Mr. Anwar', 
+   ]
+);
+
+is(secretSanta(
+     'Mr. Wall',
+     'Mrs. Wall',
+     'Mr. Anwar',
+   ),
+   [
+    'Mr. Anwar -> Mrs. Wall',
+    'Mr. Wall -> Mr. Anwar',
+    'Mrs. Wall -> Mr. Wall', 
+   ]
+);
+
+done_testing;
diff --git a/challenge-247/perlboy1967/perl/ch2.pl b/challenge-247/perlboy1967/perl/ch2.pl
new file mode 100755
index 0000000000..62f9106db7
--- /dev/null
+++ b/challenge-247/perlboy1967/perl/ch2.pl
@@ -0,0 +1,49 @@
+#!/bin/perl
+
+=pod
+
+The Weekly Challenge - 247
+- https://theweeklychallenge.org/blog/perl-weekly-challenge-247
+
+Author: Niels 'PerlBoy' van Dijke
+
+Task 2: Most Frequent Letter Pair
+Submitted by: Jorg Sommrey
+
+You are given a string S of lower case letters 'a'..'z'.
+
+Write a script that finds the pair of consecutive letters in S that appears most frequently.
+If there is more than one such pair, chose the one that is the lexicographically first.
+
+=cut
+
+use v5.32;
+use common::sense;
+use feature qw(signatures);
+
+use Test2::V0;
+
+use List::Util qw(uniq max);
+use Algorithm::Combinatorics qw(variations);
+
+sub mostFrequentLetterPair($string) {
+  my @chars = uniq sort split //, $string;
+  my $l = length $string;
+
+  my %count;
+
+  for my $p (variations(\@chars,2)) {
+    next if $$p[0] eq $$p[1];
+    my $c2 = $$p[0].$$p[1];
+    $count{$c2} = ($l - length ($string =~ s/$c2//gr))/2;
+  }
+
+  my $m = max(values %count);
+
+  return (sort grep { $count{$_} == $m } keys %count)[0];
+}
+
+is(mostFrequentLetterPair('abcdbca'),'bc');
+is(mostFrequentLetterPair('cdeabeabfcdfabgcd'),'ab');
+
+done_testing;
-- 
cgit 


From 6b06b651e965daa48ef377714890218037768e68 Mon Sep 17 00:00:00 2001
From: Peter Campbell Smith <pj.campbell.smith@gmail.com>
Date: Mon, 11 Dec 2023 16:39:15 +0000
Subject: Week 247 - Christmas is coming!

---
 challenge-247/peter-campbell-smith/blog.txt     |  1 +
 challenge-247/peter-campbell-smith/perl/ch-1.pl | 55 +++++++++++++++++++++++++
 challenge-247/peter-campbell-smith/perl/ch-2.pl | 37 +++++++++++++++++
 3 files changed, 93 insertions(+)
 create mode 100644 challenge-247/peter-campbell-smith/blog.txt
 create mode 100755 challenge-247/peter-campbell-smith/perl/ch-1.pl
 create mode 100755 challenge-247/peter-campbell-smith/perl/ch-2.pl

diff --git a/challenge-247/peter-campbell-smith/blog.txt b/challenge-247/peter-campbell-smith/blog.txt
new file mode 100644
index 0000000000..0734455d93
--- /dev/null
+++ b/challenge-247/peter-campbell-smith/blog.txt
@@ -0,0 +1 @@
+http://ccgi.campbellsmiths.force9.co.uk/challenge/247
diff --git a/challenge-247/peter-campbell-smith/perl/ch-1.pl b/challenge-247/peter-campbell-smith/perl/ch-1.pl
new file mode 100755
index 0000000000..9c6725c2db
--- /dev/null
+++ b/challenge-247/peter-campbell-smith/perl/ch-1.pl
@@ -0,0 +1,55 @@
+#!/usr/bin/perl
+
+use v5.26;    # The Weekly Challenge - 2023-12-11
+use utf8;     # Week 247 task 1 - Secret santa
+use strict;   # Peter Campbell Smith
+use warnings; # Blog: http://ccgi.campbellsmiths.force9.co.uk/challenge
+
+secret_santa('Mr. Wall', 'Mrs. Wall', 'Mr. Anwar', 
+	'Mrs. Anwar', 'Mr. Conway', 'Mr. Cross', 
+	'Miss Anwar', 'Dr Anwar', 'Lord Anwar');
+
+secret_santa('Rudolph Reindeer', 'Dasher Reindeer', 'Dancer Reindeer',
+	'Prancer Reindeer', 'Vixen Reindeer','Comet Reindeer',
+	'Cupid Reindeer', 'Donner Reindeer', 'Blitzen Reindeer',
+	'Santa Claus', 'Mrs Claus', 'Subordinate Claus');
+				 
+sub secret_santa {
+	
+	my (%people, %recipient, $d, $r, $result, $list, $j);
+	
+	# initialise
+	$people{$_} = int(rand(899) + 101)  for (@_);
+	$list = '   ';
+	
+	# find someone with a different surname
+	D: for $d (sort {$people{$a} <=> $people{$b}} keys %people) {
+		$list .= $d . ($j ++ % 3 == 2 ? qq[,\n   ] : ', ');
+		for $r (sort {$people{$b} <=> $people{$a}} keys %people) {
+			next if ($d eq $r or $people{$r} == 0);
+			if (surname($d) ne surname($r)) {
+				$result .= qq[   $d -> $r\n];
+				$people{$r} = 0;
+				next D;
+			}
+		}
+		
+		# no luck, so try for wih the same one
+		for $r (sort {$people{$a} <=> $people{$b}} keys %people) {
+			next if ($d eq $r or $people{$r} == 0);
+			$result .= qq[   $d -> $r\n];
+			$people{$r} = 0;
+			next D;
+		}	
+	}
+	
+	# show results
+	$list =~ s|,[\n ]+$||;
+	say qq[\nInput:\n$list];
+	say qq[Output:\n] . substr($result, 0, -1);
+}
+
+sub surname {	
+	$_[0] =~ m|([-a-zA-Z']*)$|;
+	return $1;
+}
\ No newline at end of file
diff --git a/challenge-247/peter-campbell-smith/perl/ch-2.pl b/challenge-247/peter-campbell-smith/perl/ch-2.pl
new file mode 100755
index 0000000000..3c61498857
--- /dev/null
+++ b/challenge-247/peter-campbell-smith/perl/ch-2.pl
@@ -0,0 +1,37 @@
+#!/usr/bin/perl
+
+use v5.26;    # The Weekly Challenge - 2023-12-11
+use utf8;     # Week 247 task 2 - Most frequent letter pair
+use strict;   # Peter Campbell Smith
+use warnings; # Blog: http://ccgi.campbellsmiths.force9.co.uk/challenge
+
+most_frequent('cdeabeabfcdfabgcd');
+most_frequent('abcdefghijklmnopqrstuvwxyz');
+most_frequent('nowisthetimeforallgoodmentocometotheaidoftheparty');
+most_frequent('zyxwvutsrqponmlkjihgfedcba');
+most_frequent('ghghijijij');
+
+sub most_frequent {
+	
+	my ($x, $string, $pair, $count, $best, $most);
+	
+	# initialise
+	$string = $_[0];
+	$best = '';
+	$most = 0;
+	
+	# loop over ab, bc, cd ...
+	for $x ('a' .. 'y') {
+		$pair = $x . chr(ord($x) + 1);
+		
+		# count matches in string
+		$count = () = $string =~ m|$pair|g;
+		if ($count > $most) {
+			$best = $pair;
+			$most = $count;
+		}
+	}
+	
+	# output results
+	say qq[\nInput:  \$s = '$string'\nOutput: ] . ($most ? qq['$best' x $most] : 'none');
+}
-- 
cgit 


From 18ccf43b3283e1e5057bcae693801b906a520fb7 Mon Sep 17 00:00:00 2001
From: pme <hauptadler@gmail.com>
Date: Mon, 11 Dec 2023 18:57:02 +0100
Subject: challenge-247

---
 challenge-247/peter-meszaros/perl/ch-1.pl | 122 ++++++++++++++++++++++++++++++
 challenge-247/peter-meszaros/perl/ch-2.pl |  55 ++++++++++++++
 2 files changed, 177 insertions(+)
 create mode 100755 challenge-247/peter-meszaros/perl/ch-1.pl
 create mode 100755 challenge-247/peter-meszaros/perl/ch-2.pl

diff --git a/challenge-247/peter-meszaros/perl/ch-1.pl b/challenge-247/peter-meszaros/perl/ch-1.pl
new file mode 100755
index 0000000000..9527af57a6
--- /dev/null
+++ b/challenge-247/peter-meszaros/perl/ch-1.pl
@@ -0,0 +1,122 @@
+#!/usr/bin/env perl
+#
+# Secret Santa is a Christmas tradition in which members of a group are
+# randomly assigned a person to whom they give a gift.
+# 
+# You are given a list of names. Write a script that tries to team persons from
+# different families.
+# Example 1
+# 
+# The givers are randomly chosen but don't share family names with the
+# receivers.
+# 
+# Input: @names = ('Mr. Wall',
+#                  'Mrs. Wall',
+#                  'Mr. Anwar',
+#                  'Mrs. Anwar',
+#                  'Mr. Conway',
+#                  'Mr. Cross',
+#                 );
+# 
+# Output:
+# 
+#     Mr. Conway -> Mr. Wall
+#     Mr. Anwar  -> Mrs. Wall
+#     Mrs. Wall  -> Mr. Anwar
+#     Mr. Cross  -> Mrs. Anwar
+#     Mr. Wall   -> Mr. Conway
+#     Mrs. Anwar -> Mr. Cross
+# 
+# Example 2
+# 
+# One gift is given to a family member.
+# 
+# Input: @names = ('Mr. Wall',
+#                  'Mrs. Wall',
+#                  'Mr. Anwar',
+#                 );
+# 
+# Output:
+# 
+#     Mr. Anwar -> Mr. Wall
+#     Mr. Wall  -> Mrs. Wall
+#     Mrs. Wall -> Mr. Anwar
+
+
+use strict;
+use warnings;
+use Test::More;
+use Data::Dumper;
+use Algorithm::Combinatorics qw/combinations/;
+
+my $cases = [
+    ['Mr. Wall',
+     'Mrs. Wall',
+     'Mr. Anwar',
+     'Mrs. Anwar',
+     'Mr. Conway',
+     'Mr. Cross',
+    ],
+    ['Mr. Wall',
+     'Mrs. Wall',
+     'Mr. Anwar',
+    ],
+];
+
+sub secret_santa
+{
+    my $names = shift;
+
+	# generate all possible actions
+    my @actions;
+    for my $p1 (@$names) {
+        my ($t1, $n1) = split(' ', $p1);
+        for my $p2 (@$names) {
+            next if $p1 eq $p2;
+            my ($t2, $n2) = split(' ', $p2);
+            next if $n1 eq $n2;
+            push @actions, [$p1, $p2];
+        }
+    }
+
+	# generate all possible actions sets
+	my $ret = 0;
+    my $iter = combinations(\@actions, scalar @$names);
+    while (my $c = $iter->next) {
+		my %stat = map { $_ => []} @$names;
+
+		# collect statistics on actions
+		for my $action (@$c) {
+			my ($n0, $n1) = @$action;
+			$stat{$n0}->[0]++;
+			$stat{$n1}->[1]++;
+		}
+
+		# evaluate statistics
+		my $ok = 1;
+		for my $k (keys %stat) {
+			my ($v1, $v2) = $stat{$k}->@*;
+			if (!defined $v1 or $v1 != 1 or !defined $v2 or $v2 != 1) {
+				$ok = 0;
+				last;
+			}
+		}
+		# print the winner
+		if ($ok) {
+			for my $action (@$c) {
+				my ($n0, $n1) = @$action;
+				print "$n0 -> $n1\n";
+			}
+			$ret = 1;
+			last;
+		}
+    }
+
+    return $ret;
+}
+
+is(secret_santa($cases->[0]), 1, 'big set');
+is(secret_santa($cases->[1]), 0, 'small set');
+done_testing();
+
+exit 0;
diff --git a/challenge-247/peter-meszaros/perl/ch-2.pl b/challenge-247/peter-meszaros/perl/ch-2.pl
new file mode 100755
index 0000000000..1fc9363f1c
--- /dev/null
+++ b/challenge-247/peter-meszaros/perl/ch-2.pl
@@ -0,0 +1,55 @@
+#!/usr/bin/env perl
+#
+# You are given a string S of lower case letters 'a'..'z'.
+# 
+# Write a script that finds the pair of consecutive letters in S that appears
+# most frequently. If there is more than one such pair, chose the one that is the
+# lexicographically first.
+# Example 1
+# 
+# Input: $s = 'abcdbca'
+# Output: 'bc'
+# 
+# 'bc' appears twice in `$s`
+# 
+# Example 2
+# 
+# Input: $s = 'cdeabeabfcdfabgcd'
+# Output: 'ab'
+# 
+# 'ab' and 'cd' both appear three times in $s and 'ab' is lexicographically
+# smaller than 'cd'.
+# 
+
+use strict;
+use warnings;
+use Test::More;
+use Data::Dumper;
+
+my $cases = [
+	'abcdbca',
+	'cdeabeabfcdfabgcd',
+];
+
+sub most_frequent_pair
+{
+    my $s = shift;
+
+    my @s = split('', $s);
+    my %h;
+    for my $l (0..($#s-1)) {
+        $h{$s[$l].$s[$l+1]}++;
+    }
+    return (sort {$h{$b} == $h{$a} ? 
+					$a cmp $b :
+                    $h{$b} <=> $h{$a}
+				 } keys %h)[0];
+}
+
+is(most_frequent_pair($cases->[0]),  'bc', 'abcdbca');
+is(most_frequent_pair($cases->[1]),  'ab', 'cdeabeabfcdfabgcd');
+done_testing();
+
+exit 0;
+
+         
-- 
cgit 


From e02f9a7b14d59e6c4be8d0f2dbd0fae021111654 Mon Sep 17 00:00:00 2001
From: Mark <53903062+andemark@users.noreply.github.com>
Date: Mon, 11 Dec 2023 20:56:13 +0000
Subject: Challenge 247 Solutions (Raku)

---
 challenge-247/mark-anderson/raku/ch-1.raku | 23 +++++++++++++++++++++++
 challenge-247/mark-anderson/raku/ch-2.raku | 18 +++++++++++++++++-
 2 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/challenge-247/mark-anderson/raku/ch-1.raku b/challenge-247/mark-anderson/raku/ch-1.raku
index a3ae0d336a..723065ba5a 100644
--- a/challenge-247/mark-anderson/raku/ch-1.raku
+++ b/challenge-247/mark-anderson/raku/ch-1.raku
@@ -19,6 +19,29 @@ is-deeply secret-santa(["Mr. Wall", "Mrs. Wall", "Mr. Anwar"]),
               "Mrs. Wall" => "Mr. Wall"
           }
 
+# Example from Peter Campbell Smith
+is-deeply secret-santa(["Rudolph Reindeer", "Dasher Reindeer", 
+                        "Dancer Reindeer",  "Prancer Reindeer", 
+                        "Vixen Reindeer",   "Comet Reindeer",
+	                    "Cupid Reindeer",   "Donner Reindeer", 
+                        "Blitzen Reindeer", "Santa Claus", 
+                        "Mrs Claus",        "Subordinate Claus"]),
+
+          {
+              "Donner Reindeer"   => "Mrs Claus",
+              "Blitzen Reindeer"  => "Subordinate Claus",
+              "Cupid Reindeer"    => "Santa Claus",
+              "Dancer Reindeer"   => "Dasher Reindeer",
+              "Comet Reindeer"    => "Vixen Reindeer",
+              "Dasher Reindeer"   => "Rudolph Reindeer",
+              "Vixen Reindeer"    => "Prancer Reindeer",
+              "Rudolph Reindeer"  => "Blitzen Reindeer",
+              "Prancer Reindeer"  => "Dancer Reindeer",
+              "Santa Claus"       => "Comet Reindeer",
+              "Subordinate Claus" => "Donner Reindeer",
+              "Mrs Claus"         => "Cupid Reindeer",
+          }
+
 sub secret-santa(@names)
 {
     my %surname = @names.classify({ .words[1] });
diff --git a/challenge-247/mark-anderson/raku/ch-2.raku b/challenge-247/mark-anderson/raku/ch-2.raku
index 532186b18e..82ab53feb8 100644
--- a/challenge-247/mark-anderson/raku/ch-2.raku
+++ b/challenge-247/mark-anderson/raku/ch-2.raku
@@ -4,7 +4,23 @@ use Test;
 is most-freq-pair("abcdbca"),           "bc";
 is most-freq-pair("cdeabeabfcdfabgcd"), "ab";
 
-sub most-freq-pair($str)
+say most-freq-pair([~] ("a".."z").roll(100_000));
+
+multi most-freq-pair($str where .chars < 100_000)
 {
     ($str ~~ m:ov/../)>>.Str.Bag.maxpairs.sort.head.key
 }
+
+multi most-freq-pair($str)
+{
+    my $len = ($str.chars / $*KERNEL.cpu-cores).ceiling;
+
+    my @promises = (^$*KERNEL.cpu-cores).map(
+    { 
+       start { ($str.substr(($len * $_), $len+1) ~~ m:ov/../)>>.Str.Bag }
+    }); 
+
+    await @promises;
+
+    ([(+)] @promises>>.result).maxpairs.sort.head.key
+}
-- 
cgit 


From 42019e9f67123f9aade27603bda5ae1454dc23be Mon Sep 17 00:00:00 2001
From: Mark <53903062+andemark@users.noreply.github.com>
Date: Mon, 11 Dec 2023 21:00:38 +0000
Subject: Challenge 247 Solutions (Raku)

---
 challenge-247/mark-anderson/raku/ch-1.raku | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/challenge-247/mark-anderson/raku/ch-1.raku b/challenge-247/mark-anderson/raku/ch-1.raku
index 723065ba5a..9ed0228dbd 100644
--- a/challenge-247/mark-anderson/raku/ch-1.raku
+++ b/challenge-247/mark-anderson/raku/ch-1.raku
@@ -23,7 +23,7 @@ is-deeply secret-santa(["Mr. Wall", "Mrs. Wall", "Mr. Anwar"]),
 is-deeply secret-santa(["Rudolph Reindeer", "Dasher Reindeer", 
                         "Dancer Reindeer",  "Prancer Reindeer", 
                         "Vixen Reindeer",   "Comet Reindeer",
-	                    "Cupid Reindeer",   "Donner Reindeer", 
+                        "Cupid Reindeer",   "Donner Reindeer", 
                         "Blitzen Reindeer", "Santa Claus", 
                         "Mrs Claus",        "Subordinate Claus"]),
 
-- 
cgit 


From 89ad3788c843e54cf9fa097a7e1010219b889cc9 Mon Sep 17 00:00:00 2001
From: Mark <53903062+andemark@users.noreply.github.com>
Date: Mon, 11 Dec 2023 21:07:52 +0000
Subject: Challenge 247 Solutions (Raku)

---
 challenge-247/mark-anderson/raku/ch-1.raku | 1 -
 1 file changed, 1 deletion(-)

diff --git a/challenge-247/mark-anderson/raku/ch-1.raku b/challenge-247/mark-anderson/raku/ch-1.raku
index 9ed0228dbd..fe6c4163c4 100644
--- a/challenge-247/mark-anderson/raku/ch-1.raku
+++ b/challenge-247/mark-anderson/raku/ch-1.raku
@@ -26,7 +26,6 @@ is-deeply secret-santa(["Rudolph Reindeer", "Dasher Reindeer",
                         "Cupid Reindeer",   "Donner Reindeer", 
                         "Blitzen Reindeer", "Santa Claus", 
                         "Mrs Claus",        "Subordinate Claus"]),
-
           {
               "Donner Reindeer"   => "Mrs Claus",
               "Blitzen Reindeer"  => "Subordinate Claus",
-- 
cgit 


From 908aa39a6d95d19cbe8f59dc56918676ccca5976 Mon Sep 17 00:00:00 2001
From: Dave Jacoby <jacoby.david@gmail.com>
Date: Mon, 11 Dec 2023 16:08:54 -0500
Subject: solved 247

---
 challenge-247/dave-jacoby/blog.txt     |  1 +
 challenge-247/dave-jacoby/perl/ch-1.pl | 62 ++++++++++++++++++++++++++++++++++
 challenge-247/dave-jacoby/perl/ch-2.pl | 32 ++++++++++++++++++
 3 files changed, 95 insertions(+)
 create mode 100644 challenge-247/dave-jacoby/blog.txt
 create mode 100644 challenge-247/dave-jacoby/perl/ch-1.pl
 create mode 100644 challenge-247/dave-jacoby/perl/ch-2.pl

diff --git a/challenge-247/dave-jacoby/blog.txt b/challenge-247/dave-jacoby/blog.txt
new file mode 100644
index 0000000000..6bd07983bc
--- /dev/null
+++ b/challenge-247/dave-jacoby/blog.txt
@@ -0,0 +1 @@
+https://jacoby.github.io/2023/12/11/partidges-and-pair-trees-weekly-challenge-247.html
diff --git a/challenge-247/dave-jacoby/perl/ch-1.pl b/challenge-247/dave-jacoby/perl/ch-1.pl
new file mode 100644
index 0000000000..d96619aa19
--- /dev/null
+++ b/challenge-247/dave-jacoby/perl/ch-1.pl
@@ -0,0 +1,62 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use experimental qw{ say postderef signatures state };
+
+my @examples = (
+
+    [
+        'Mr. Wall',
+        'Mrs. Wall',
+        'Mr. Anwar',
+        'Mrs. Anwar',
+        'Mr. Conway',
+        'Mr. Cross',
+    ],
+
+    [ 'Mr. Wall', 'Mrs. Wall', 'Mr. Anwar', ],
+);
+
+for my $example (@examples) {
+    my %output = secret_santa( $example->@* );
+    my $input = join ",\n\t",
+        map  { qq{"$_"} }                               # quote surname
+        map  { $_->[0] }                                # remove surname element
+        sort { $a->[1] cmp $b->[1] }                    # sort on surname
+        map  { [ $_, ( reverse split /\s/, $_ )[0] ] }  # start schartzian transform on surname
+        sort { $a cmp $b } $example->@*;                # sort alphabetically for consistency
+    my $output = join "\n\t",
+        map  { qq{$_ -> $output{$_}} }                  # combine santa and giftee 
+        map  { $_->[0] }                                # remove surname element
+        sort { $a->[1] cmp $b->[1] }                    # sort on surname
+        map  { [ $_, ( reverse split /\s/, $_ )[0] ] }  # start schartzian transform on surname
+        sort { $a cmp $b } keys %output;                # sort alphabetically for consistency
+
+    say <<~"END";
+    Input:  \$input = (
+            $input
+            );
+    Output:
+            $output
+    END
+
+}
+
+# 1) everybody gets matched
+# 2) nobody gets matched to themself
+sub secret_santa (@input) {
+    my %done;
+
+    for my $name (@input) {
+        my %chosen = reverse %done;
+        my @others =
+            sort { rand 10 <=> rand 10 }
+            grep { $_ ne $name } @input;
+        for my $giftee (@others) {
+            next if $chosen{$giftee};
+            $done{$name} = $giftee;
+        }
+    }
+    return %done;
+}
diff --git a/challenge-247/dave-jacoby/perl/ch-2.pl b/challenge-247/dave-jacoby/perl/ch-2.pl
new file mode 100644
index 0000000000..cdc7dabc15
--- /dev/null
+++ b/challenge-247/dave-jacoby/perl/ch-2.pl
@@ -0,0 +1,32 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use experimental qw{ say postderef signatures state };
+
+my @examples = (
+
+    'abcdbca',
+    'cdeabeabfcdfabgcd',
+);
+
+for my $e (@examples) {
+    my $output = most_frequent_letter_pair($e);
+
+    say <<~"END";
+    Input:  \$input = '$e'
+    Output:          '$output'
+    END
+}
+
+sub most_frequent_letter_pair ($string) {
+    my %data;
+    for my $i ( 0 .. -2 + length $string ) {
+        my $sub = substr $string, $i, 2;
+        $data{$sub}++;
+    }
+    # ($scalar) = @list will assign the first element in the list to $scalar
+    my ($first) = sort { $data{$b} <=> $data{$a} }  # second sort on value
+        sort keys %data;                            # first sort on lexographic value
+    return $first;
+}
-- 
cgit 


From 80ae4abbbd0c764ed3452bcb9261a37d76faf7b5 Mon Sep 17 00:00:00 2001
From: Mark <53903062+andemark@users.noreply.github.com>
Date: Mon, 11 Dec 2023 21:20:42 +0000
Subject: Challenge 247 Solutions (Raku)

---
 challenge-247/mark-anderson/raku/ch-1.raku | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/challenge-247/mark-anderson/raku/ch-1.raku b/challenge-247/mark-anderson/raku/ch-1.raku
index fe6c4163c4..3e3e059503 100644
--- a/challenge-247/mark-anderson/raku/ch-1.raku
+++ b/challenge-247/mark-anderson/raku/ch-1.raku
@@ -25,9 +25,9 @@ is-deeply secret-santa(["Rudolph Reindeer", "Dasher Reindeer",
                         "Vixen Reindeer",   "Comet Reindeer",
                         "Cupid Reindeer",   "Donner Reindeer", 
                         "Blitzen Reindeer", "Santa Claus", 
-                        "Mrs Claus",        "Subordinate Claus"]),
+                        "Mrs. Claus",       "Subordinate Claus"]),
           {
-              "Donner Reindeer"   => "Mrs Claus",
+              "Donner Reindeer"   => "Mrs. Claus",
               "Blitzen Reindeer"  => "Subordinate Claus",
               "Cupid Reindeer"    => "Santa Claus",
               "Dancer Reindeer"   => "Dasher Reindeer",
@@ -38,7 +38,7 @@ is-deeply secret-santa(["Rudolph Reindeer", "Dasher Reindeer",
               "Prancer Reindeer"  => "Dancer Reindeer",
               "Santa Claus"       => "Comet Reindeer",
               "Subordinate Claus" => "Donner Reindeer",
-              "Mrs Claus"         => "Cupid Reindeer",
+              "Mrs. Claus"        => "Cupid Reindeer",
           }
 
 sub secret-santa(@names)
-- 
cgit 


From 7e80ee4cbca65a5ae322ab03d1f512201f5d029f Mon Sep 17 00:00:00 2001
From: David Ferrone <zapwai@gmail.com>
Date: Mon, 11 Dec 2023 16:58:39 -0500
Subject: Week 247

---
 challenge-247/zapwai/perl/ch-1.pl | 80 +++++++++++++++++++++++++++++++++++++++
 challenge-247/zapwai/perl/ch-2.pl | 24 ++++++++++++
 2 files changed, 104 insertions(+)
 create mode 100644 challenge-247/zapwai/perl/ch-1.pl
 create mode 100644 challenge-247/zapwai/perl/ch-2.pl

diff --git a/challenge-247/zapwai/perl/ch-1.pl b/challenge-247/zapwai/perl/ch-1.pl
new file mode 100644
index 0000000000..40a1ce096e
--- /dev/null
+++ b/challenge-247/zapwai/perl/ch-1.pl
@@ -0,0 +1,80 @@
+use v5.30;
+use Algorithm::Permute;
+my @names = ('Mr. Wall',
+	     'Mrs. Wall',
+	     'Mr. Anwar',
+	     'Mrs. Anwar',
+	     'Mr. Conway',
+	     'Mr. Cross',
+	 );
+#@names = ('Mr. Wall', 'Mrs. Wall', 'Mr. Cringle');
+
+say "Input: \@names = (". join(", ", @names) . ")";
+say "Output: ";
+my @seq;
+my @tried;
+my $endflag = 1;
+my $N = factorial(scalar @names);
+my $index = int rand $N;
+my @P;
+load_perms();
+
+do {
+    @seq = random_pls($index);
+    if (check(@seq)) {
+	$endflag = 0;
+    } else {
+	$endflag++;
+	push @tried, $index;
+	my $test_string = join(" ", @tried);
+	my $flag = 0;
+	my $x;
+	do {
+	    $x = int rand $N;
+	    unless ( $test_string =~ m/$x/ ) {
+		$flag = 1;
+	    }
+	} until ($flag);
+	$index = $x;
+    }
+} until ( ($endflag == 0) or ($endflag == $N) );
+
+foreach my $i (0 .. $#seq - 1) {
+    print $names[$seq[$i]] . " --> ";
+}
+print $names[$seq[$#seq]]."\n";
+
+
+sub load_perms {
+    my $p = Algorithm::Permute->new([0 .. $#names]);
+    while (my @perm = $p->next) {
+	push @P, \@perm;
+    }
+}
+
+sub random_pls {
+    my $index = shift;
+    return @{$P[$index]};
+}
+
+sub factorial {
+    my ($n) = @_;
+    return 1 if $n == 0;
+    return factorial($n-1) * $n;
+}
+
+sub check {
+    my @seq = @_;
+    my @surname;
+    foreach my $name (@names) {
+	my @chunk = split(" ", $name);
+	push @surname, $chunk[1];
+    }
+    for my $i (0 .. $#seq - 1) {
+	if ($surname[$seq[$i]] eq $surname[$seq[$i + 1]]) {
+	    return 0;
+	}
+    }
+    return 0 if ($surname[$seq[0]] eq $surname[$seq[$#seq]]);
+    return 1;
+}
diff --git a/challenge-247/zapwai/perl/ch-2.pl b/challenge-247/zapwai/perl/ch-2.pl
new file mode 100644
index 0000000000..ff5f27ef6a
--- /dev/null
+++ b/challenge-247/zapwai/perl/ch-2.pl
@@ -0,0 +1,24 @@
+use v5.30;
+my $s = "abcdbca";
+my $s = "cdeabeabfcdfabgcd";
+my %h;
+my @pairs;
+my $max = 0;
+foreach my $i (0 .. (length $s) - 2) {
+    my $nom = substr $s, $i, 2;
+    $h{$nom}++;
+}
+foreach my $key (keys %h) {
+    if ($max < $h{$key}) {
+	$max = $h{$key};
+    }
+}
+foreach my $key (keys %h) {
+    push @pairs, $key if ($max == $h{$key});
+}
+my $ans = $pairs[0];
+foreach my $pair ( @pairs ) {
+    $ans = $pair if ($pair le $ans);
+}
+say "Input: \$s = $s";
+say "Output: $ans";
-- 
cgit 


From 190283aa37525a7bc2797f6dbf4db84efb46b2c5 Mon Sep 17 00:00:00 2001
From: Luis Mochan <mochan@fis.unam.mx>
Date: Mon, 11 Dec 2023 21:51:21 -0600
Subject: Solve PWC247

---
 challenge-247/wlmb/blog.txt     |  1 +
 challenge-247/wlmb/perl/ch-1.pl | 26 ++++++++++++++++++++++++++
 challenge-247/wlmb/perl/ch-2.pl | 19 +++++++++++++++++++
 3 files changed, 46 insertions(+)
 create mode 100644 challenge-247/wlmb/blog.txt
 create mode 100755 challenge-247/wlmb/perl/ch-1.pl
 create mode 100755 challenge-247/wlmb/perl/ch-2.pl

diff --git a/challenge-247/wlmb/blog.txt b/challenge-247/wlmb/blog.txt
new file mode 100644
index 0000000000..fb01e3096f
--- /dev/null
+++ b/challenge-247/wlmb/blog.txt
@@ -0,0 +1 @@
+https://wlmb.github.io/2023/12/11/PWC247/
diff --git a/challenge-247/wlmb/perl/ch-1.pl b/challenge-247/wlmb/perl/ch-1.pl
new file mode 100755
index 0000000000..5f20b58274
--- /dev/null
+++ b/challenge-247/wlmb/perl/ch-1.pl
@@ -0,0 +1,26 @@
+#!/usr/bin/env perl
+# Perl weekly challenge 247
+# Task 1:  Secret Santa
+#
+# See https://wlmb.github.io/2023/12/11/PWC247/#task-1-secret-santa
+use v5.36;
+use experimental qw(postderef);
+my %last_name;
+my %person;
+# Input from STDIN, one name per line
+while(<>){
+    chomp;
+    my (undef,$last)=split " ";
+    $last_name{$_}=$last;
+    push $person{$last}->@*, $_;
+}
+my @families=sort {$person{$b}->@*<=>$person{$a}->@*} keys %person;
+my $first_giver;
+while(@families){
+    my $family_giver=shift @families;
+    my $giver=shift $person{$family_giver}->@*;
+    $first_giver//=$giver;
+    push @families, $family_giver if $person{$family_giver}->@*;
+    my $receiver=$families[0]?$person{$families[0]}[0]:$first_giver;
+    say "$giver -> $receiver";
+}
diff --git a/challenge-247/wlmb/perl/ch-2.pl b/challenge-247/wlmb/perl/ch-2.pl
new file mode 100755
index 0000000000..1bb4c00ce0
--- /dev/null
+++ b/challenge-247/wlmb/perl/ch-2.pl
@@ -0,0 +1,19 @@
+#!/usr/bin/env perl
+# Perl weekly challenge 247
+# Task 2:  Most Frequent Letter Pair
+#
+# See https://wlmb.github.io/2023/12/11/PWC247/#task-2-most-frequent-letter-pair
+use v5.36;
+die <<~"FIN" unless @ARGV;
+    Usage: $0 S1 [S2...]
+    to find the most frequent pair of consecutive letters
+    from each of the strings S1, S2...
+    FIN
+for(@ARGV){
+    my @letters=split "";
+    my $first=shift @letters;
+    my %count;
+    $count{$_}++ for map{my $previous=$first; $first=$_; "$previous$first"}@letters;
+    my @sorted =sort{$count{$b}<=>$count{$a}||$a cmp $b} keys %count;
+    say "$_ -> $sorted[0]"
+}
-- 
cgit 


From 3839b4b035697af7edd9ac1ad6c720ab6cd003e0 Mon Sep 17 00:00:00 2001
From: Roger Bell_West <roger@firedrake.org>
Date: Tue, 12 Dec 2023 09:39:32 +0000
Subject: RogerBW solutions for challenge no. 247

---
 challenge-247/roger-bell-west/javascript/ch-1.js |  52 +++++
 challenge-247/roger-bell-west/javascript/ch-2.js |  32 +++
 challenge-247/roger-bell-west/kotlin/ch-1.kt     |  50 +++++
 challenge-247/roger-bell-west/kotlin/ch-2.kt     |  31 +++
 challenge-247/roger-bell-west/lua/ch-1.lua       |  69 ++++++
 challenge-247/roger-bell-west/lua/ch-2.lua       |  40 ++++
 challenge-247/roger-bell-west/perl/ch-1.pl       |  45 ++++
 challenge-247/roger-bell-west/perl/ch-2.pl       |  23 ++
 challenge-247/roger-bell-west/postscript/ch-1.ps | 192 ++++++++++++++++
 challenge-247/roger-bell-west/postscript/ch-2.ps | 272 +++++++++++++++++++++++
 challenge-247/roger-bell-west/python/ch-1.py     |  40 ++++
 challenge-247/roger-bell-west/python/ch-2.py     |  25 +++
 challenge-247/roger-bell-west/raku/ch-1.p6       |  43 ++++
 challenge-247/roger-bell-west/raku/ch-2.p6       |  19 ++
 challenge-247/roger-bell-west/ruby/ch-1.rb       |  52 +++++
 challenge-247/roger-bell-west/ruby/ch-2.rb       |  31 +++
 challenge-247/roger-bell-west/rust/ch-1.rs       |  61 +++++
 challenge-247/roger-bell-west/rust/ch-2.rs       |  30 +++
 challenge-247/roger-bell-west/scala/ch-1.scala   |  51 +++++
 challenge-247/roger-bell-west/scala/ch-2.scala   |  33 +++
 challenge-247/roger-bell-west/tests.yaml         |  22 ++
 21 files changed, 1213 insertions(+)
 create mode 100755 challenge-247/roger-bell-west/javascript/ch-1.js
 create mode 100755 challenge-247/roger-bell-west/javascript/ch-2.js
 create mode 100644 challenge-247/roger-bell-west/kotlin/ch-1.kt
 create mode 100644 challenge-247/roger-bell-west/kotlin/ch-2.kt
 create mode 100755 challenge-247/roger-bell-west/lua/ch-1.lua
 create mode 100755 challenge-247/roger-bell-west/lua/ch-2.lua
 create mode 100755 challenge-247/roger-bell-west/perl/ch-1.pl
 create mode 100755 challenge-247/roger-bell-west/perl/ch-2.pl
 create mode 100644 challenge-247/roger-bell-west/postscript/ch-1.ps
 create mode 100644 challenge-247/roger-bell-west/postscript/ch-2.ps
 create mode 100755 challenge-247/roger-bell-west/python/ch-1.py
 create mode 100755 challenge-247/roger-bell-west/python/ch-2.py
 create mode 100755 challenge-247/roger-bell-west/raku/ch-1.p6
 create mode 100755 challenge-247/roger-bell-west/raku/ch-2.p6
 create mode 100755 challenge-247/roger-bell-west/ruby/ch-1.rb
 create mode 100755 challenge-247/roger-bell-west/ruby/ch-2.rb
 create mode 100755 challenge-247/roger-bell-west/rust/ch-1.rs
 create mode 100755 challenge-247/roger-bell-west/rust/ch-2.rs
 create mode 100644 challenge-247/roger-bell-west/scala/ch-1.scala
 create mode 100644 challenge-247/roger-bell-west/scala/ch-2.scala
 create mode 100644 challenge-247/roger-bell-west/tests.yaml

diff --git a/challenge-247/roger-bell-west/javascript/ch-1.js b/challenge-247/roger-bell-west/javascript/ch-1.js
new file mode 100755
index 0000000000..e63be00da6
--- /dev/null
+++ b/challenge-247/roger-bell-west/javascript/ch-1.js
@@ -0,0 +1,52 @@
+#! /usr/bin/node
+
+"use strict"
+
+function secretsanta(name) {
+    let family = [];
+    for (let n of name) {
+        let surname = n.split(" ");
+        family.push(surname[surname.length - 1]);
+    }
+    let receivers = new Set(Array(name.length).fill().map((element, index) => index));
+    let gifting = [];
+    for (let giver = 0; giver < name.length; giver++) {
+        let done = false;
+        let r = 0;
+        for (let recipient of receivers) {
+            if (family[giver] != family[recipient]) {
+                r = recipient;
+                done = true;
+                break;
+            }
+        }
+        if (!done) {
+            for (let recipient of receivers) {
+                if (recipient != giver) {
+                    r = recipient;
+                    break;
+                }
+            }
+        }
+        receivers.delete(r)
+        gifting.push([name[giver], name[r]]);
+    }
+    for (let p of gifting) {
+        console.log("%s -> %s", p[0], p[1]);
+    }
+    console.log("");
+    return true;
+}
+
+if (secretsanta(['Mr. Wall', 'Mrs. Wall', 'Mr. Anwar', 'Mrs. Anwar', 'Mr. Conway', 'Mr. Cross'])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (secretsanta(['Mr. Wall', 'Mrs. Wall', 'Mr. Anwar'])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write("\n");
diff --git a/challenge-247/roger-bell-west/javascript/ch-2.js b/challenge-247/roger-bell-west/javascript/ch-2.js
new file mode 100755
index 0000000000..6ba8875493
--- /dev/null
+++ b/challenge-247/roger-bell-west/javascript/ch-2.js
@@ -0,0 +1,32 @@
+#! /usr/bin/node
+
+"use strict"
+
+function mostfrequentletterpair(s) {
+    let f = new Map;
+    for (let i = 0; i < s.length - 1; i++) {
+        let pair = s.substring(i, i + 2);
+        if (f.has(pair)) {
+            f.set(pair,f.get(pair)+1);
+        } else {
+            f.set(pair,1);
+        }
+    }
+    const m = Math.max(...f.values());
+    let l = Array.from(f.keys()).filter(i => f.get(i) == m);
+    l.sort();
+    return l[0];
+}
+
+if (mostfrequentletterpair('abcdbca') == 'bc') {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (mostfrequentletterpair('cdeabeabfcdfabgcd') == 'ab') {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write("\n");
diff --git a/challenge-247/roger-bell-west/kotlin/ch-1.kt b/challenge-247/roger-bell-west/kotlin/ch-1.kt
new file mode 100644
index 0000000000..9aab0e29d7
--- /dev/null
+++ b/challenge-247/roger-bell-west/kotlin/ch-1.kt
@@ -0,0 +1,50 @@
+fun secretsanta(name: List<String>): Boolean {
+    val family: List<String> = name.map{n -> n.split(" ").last()}.toList()
+    var receivers = generateSequence(0) { it + 1 }.take(name.size).toMutableSet()
+    var gifting = ArrayList<List<String>>()
+    for (giver in 0 .. name.size - 1) {
+        var done = false
+        var r = 0
+        for (recipient in receivers) {
+            if (family[giver] != family[recipient]) {
+                r = recipient
+                done = true
+                break
+            }
+        }
+        if (!done) {
+            for (recipient in receivers) {
+                if (giver != recipient) {
+                    r = recipient
+                    break
+                }
+            }
+        }
+        receivers.remove(r)
+        gifting.add(listOf(name[giver], name[r]))
+    }
+    for (p in gifting) {
+        print(p[0])
+        print(" -> ")
+        println(p[1])
+    }
+    println("")
+    return true;
+}
+
+fun main() {
+
+    if (secretsanta(listOf("Mr. Wall", "Mrs. Wall", "Mr. Anwar", "Mrs. Anwar", "Mr. Conway", "Mr. Cross"))) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (secretsanta(listOf("Mr. Wall", "Mrs. Wall", "Mr. Anwar"))) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    println("")
+
+}
diff --git a/challenge-247/roger-bell-west/kotlin/ch-2.kt b/challenge-247/roger-bell-west/kotlin/ch-2.kt
new file mode 100644
index 0000000000..6ada6d0aa3
--- /dev/null
+++ b/challenge-247/roger-bell-west/kotlin/ch-2.kt
@@ -0,0 +1,31 @@
+  fun mostfrequentletterpair(s: String): String {
+    var f = mutableMapOf<String, Int>()
+    for ( i in 0 .. s.length - 2 ) {
+      val ss = s.substring(i,i + 2)
+      var nv = 1
+      if (f.containsKey(ss)) {
+        nv = 1 + f.getValue(ss)
+      }
+      f[ss] = nv
+    }
+    val m = f.values.maxOrNull()!!
+    val l = f.keys.filter{i -> f[i] == m}.toList().sorted()
+    return l[0]
+  }
+
+fun main() {
+
+    if (mostfrequentletterpair("abcdbca") == "bc") {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (mostfrequentletterpair("cdeabeabfcdfabgcd") == "ab") {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    println("")
+
+}
diff --git a/challenge-247/roger-bell-west/lua/ch-1.lua b/challenge-247/roger-bell-west/lua/ch-1.lua
new file mode 100755
index 0000000000..9b1bf20f97
--- /dev/null
+++ b/challenge-247/roger-bell-west/lua/ch-1.lua
@@ -0,0 +1,69 @@
+#! /usr/bin/lua
+
+-- bart at https://stackoverflow.com/questions/1426954/split-string-in-lua
+function split(inputstr, sep)
+   sep=sep or '%s'
+   local t={}
+   for field,s in string.gmatch(inputstr, "([^"..sep.."]*)("..sep.."?)") do
+      table.insert(t,field)
+      if s=="" then
+         return t
+      end
+   end
+end
+
+function secretsanta(name)
+   local family = {}
+   for _, n in ipairs(name) do
+      local surname = split(n, " ")
+      table.insert(family, surname[#surname])
+   end
+   local receivers = {}
+   for n = 1, #name do
+      receivers[n] = true
+   end
+   local gifting = {}
+   for giver = 1, #name do
+      local done = false
+      local r = 0
+      for recipient, _ in pairs(receivers) do
+         if family[giver] ~= family[recipient] then
+            r = recipient
+            done = true
+            break
+         end
+      end
+      if not done then
+         for recipient, _ in pairs(receivers) do
+            if giver ~= recipient then
+               r = recipient
+               break
+            end
+         end
+      end
+      receivers[r] = nil
+      table.insert(gifting, {name[giver], name[r]})
+   end
+   for _, p in ipairs(gifting) do
+      io.write(p[1])
+      io.write(" -> ")
+      print(p[2])
+   end
+   print("")
+   return true
+end
+
+if secretsanta({"Mr. Wall", "Mrs. Wall", "Mr. Anwar", "Mrs. Anwar", "Mr. Conway", "Mr. Cross"}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if secretsanta({"Mr. Wall", "Mrs. Wall", "Mr. Anwar"}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+print("")
+
diff --git a/challenge-247/roger-bell-west/lua/ch-2.lua b/challenge-247/roger-bell-west/lua/ch-2.lua
new file mode 100755
index 0000000000..e3bccde3d7
--- /dev/null
+++ b/challenge-247/roger-bell-west/lua/ch-2.lua
@@ -0,0 +1,40 @@
+#! /usr/bin/lua
+
+function mostfrequentletterpair(s)
+   local f = {}
+   local m = 0
+   for i = 0,string.len(s) - 1 do
+      pair = string.sub(s, i, i + 1)
+      if f[pair] == nil then
+         f[pair] = 1
+      else
+         f[pair] = f[pair] + 1
+         if f[pair] > m then
+            m = f[pair]
+         end
+      end
+   end
+   local l = {}
+   for k, v in pairs(f) do
+      if v == m then
+         table.insert(l, k)
+      end
+   end
+   table.sort(l)
+   return l[1]
+end
+
+if mostfrequentletterpair("abcdbca") == "bc" then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if mostfrequentletterpair("cdeabeabfcdfabgcd") == "ab" then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+print("")
+
diff --git a/challenge-247/roger-bell-west/perl/ch-1.pl b/challenge-247/roger-bell-west/perl/ch-1.pl
new file mode 100755
index 0000000000..79bec4edbe
--- /dev/null
+++ b/challenge-247/roger-bell-west/perl/ch-1.pl
@@ -0,0 +1,45 @@
+#! /usr/bin/perl
+
+use strict;
+use warnings;
+use experimental 'signatures';
+
+use Test::More tests => 2;
+
+is(secretsanta(['Mr. Wall', 'Mrs. Wall', 'Mr. Anwar', 'Mrs. Anwar', 'Mr. Conway', 'Mr. Cross']), 1, 'example 1');
+is(secretsanta(['Mr. Wall', 'Mrs. Wall', 'Mr. Anwar']), 1, 'example 2');
+
+sub secretsanta($name) {
+  my @family;
+  foreach my $n (@{$name}) {
+    push @family, (split(' ', $n))[-1];
+  }
+  my %receivers = map {$_ => 1} (0 .. $#{$name});
+  my @gifting;
+  foreach my $giver (0 .. $#{$name}) {
+    my $done = 0;
+    my $r = 0;
+    foreach my $recipient (keys %receivers) {
+      if ($family[$giver] ne $family[$recipient]) {
+        $r = $recipient;
+        $done = 1;
+        last;
+      }
+    }
+    if (!$done) {
+      foreach my $recipient (keys %receivers) {
+        if ($recipient != $giver) {
+          $r = $recipient;
+          last;
+        }
+      }
+    }
+    delete $receivers{$r};
+    push @gifting, [$name->[$giver], $name->[$r]];
+  }
+  foreach my $p (@gifting) {
+    print("$p->[0] -> $p->[1]\n");
+  }
+  print "\n";
+  return 1;
+}
diff --git a/challenge-247/roger-bell-west/perl/ch-2.pl b/challenge-247/roger-bell-west/perl/ch-2.pl
new file mode 100755
index 0000000000..cb015363d1
--- /dev/null
+++ b/challenge-247/roger-bell-west/perl/ch-2.pl
@@ -0,0 +1,23 @@
+#! /usr/bin/perl
+
+use strict;
+use warnings;
+use experimental 'signatures';
+
+use Test::More tests => 2;
+
+is(mostfrequentletterpair('abcdbca'), 'bc', 'example 1');
+is(mostfrequentletterpair('cdeabeabfcdfabgcd'), 'ab', 'example 2');
+
+use List::Util qw(max);
+
+sub mostfrequentletterpair($s) {
+  my %f;
+  foreach my $i (0 .. length($s) - 2) {
+    my $pair = substr($s, $i, 2);
+    $f{$pair}++;
+  }
+  my $m = max(values %f);
+  my @l = sort {$a cmp $b} grep {$f{$_} == $m} keys %f;
+  return $l[0];
+}
diff --git a/challenge-247/roger-bell-west/postscript/ch-1.ps b/challenge-247/roger-bell-west/postscript/ch-1.ps
new file mode 100644
index 0000000000..a10b6de394
--- /dev/null
+++ b/challenge-247/roger-bell-west/postscript/ch-1.ps
@@ -0,0 +1,192 @@
+%!PS
+
+% begin included library code
+% see https://codeberg.org/Firedrake/postscript-libraries/
+/test.start {
+    print (:) print
+    /test.pass 0 def
+    /test.count 0 def
+} bind def
+
+/strsplit % (ajbjc) (j) -> [ (a) (b) (c) ]
+{
+    1 dict begin
+    /sep exch def
+    [ exch
+      {
+          dup length 0 eq {
+              pop
+              exit
+          } {
+              sep search {
+                  exch pop
+                  dup length 0 eq {
+                      pop
+                  } {
+                      exch
+                  } ifelse
+              } {
+                  ()
+              } ifelse
+          } ifelse
+      } loop
+    ]
+    end
+} bind def
+
+/deepeq {
+    2 dict begin
+    /a exch def
+    /b exch def
+    a type b type eq {
+        a type /dicttype eq {
+            a length b length eq {
+                <<
+                    a {
+                        pop
+                        true
+                    } forall
+                    b {
+                        pop
+                        true
+                    } forall
+                >>
+                true exch
+                {
+                    pop
+                    dup a exch known {
+                        dup b exch known {
+                            dup a exch get exch b exch get deepeq not {
+                                pop false
+                            } if
+                        } {
+                            false
+                        } ifelse
+                    } {
+                        false
+                    } ifelse
+                } forall
+            } {
+                false
+            } ifelse
+        } {
+            a type dup /arraytype eq exch /stringtype eq or {
+                a length b length eq {
+                    true
+                    0 1 a length 1 sub {
+                        dup a exch get exch b exch get deepeq not {
+                            pop false
+                            exit
+                        } if
+                    } for
+                } {
+                    false
+                } ifelse
+            } {
+                a b eq
+            } ifelse
+        } ifelse
+    } {
+        false
+    } ifelse
+    end
+} bind def
+
+/apush.right { % [a b] c -> [a b c]
+    exch
+    [ exch aload length 2 add -1 roll ]
+} bind def
+
+/test {
+    /test.count test.count 1 add def
+    {
+        /test.pass test.pass 1 add def
+    } {
+        ( ) print
+        test.count (....) cvs print
+        (-fail) print
+    } ifelse
+} bind def
+
+/keys { % dict -> array of dict keys
+    [ exch
+      {
+          pop
+      } forall
+    ]
+} bind def
+
+/test.end {
+    ( ) print
+    test.count 0 gt {
+        (Passed ) print
+        test.pass (...) cvs print
+        (/) print
+        test.count (...) cvs print
+        ( \() print
+        test.pass 100 mul test.count idiv (...) cvs print
+        (%\)) print
+        (\r\n) print
+    } if
+} bind def
+
+/toset { % array -> dict of (value, true)
+    << exch
+       {
+           true
+       } forall
+    >>
+} bind def
+
+
+% end included library code
+
+/secretsanta {
+    0 dict begin
+    /name exch def
+    /family [
+        name {
+            ( ) strsplit 1 get
+        } forall
+    ] def
+    /receivers [ 0 1 name length 1 sub { } for ] toset def
+    /gifting 0