2 files changed, 72 insertions, 0 deletions
diff --git a/challenge-284/jo-37/blog1.txt b/challenge-284/jo-37/blog1.txt
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index 0000000000..f5149c4012
--- /dev/null
+++ b/challenge-284/jo-37/blog1.txt
@@ -0,0 +1 @@
+https://github.sommrey.de/the-bears-den/2024/09/08/ch-284.html
diff --git a/challenge-284/jo-37/perl/ch-2a.pl b/challenge-284/jo-37/perl/ch-2a.pl
new file mode 100755
index 0000000000..1b20624871
--- /dev/null
+++ b/challenge-284/jo-37/perl/ch-2a.pl
@@ -0,0 +1,71 @@
+#!/usr/bin/perl -s
+
+use v5.24;
+use Test2::V0;
+use Tree::RB::XS ':cmp';
+use experimental 'signatures';
+
+our $examples;
+
+run_tests() if $examples;	# does not return
+
+die <<EOS unless @ARGV == 2;
+usage: $0 [-examples] [N1,N2,... M1,M2,...]
+
+-examples
+    run the examples from the challenge
+ 
+-tests
+    run some tests
+
+N1,N2,...
+    numbers in \@list1, comma and/or space separated
+
+M1,M2,...
+    numbers in \@list2, comma and/or space separated
+
+EOS
+
+
+### Input and Output
+
+say "(@{relative_sort(map [split /[, ] */, $_], @ARGV)})";
+
+
+### Implementation
+#
+# For details see:
+# https://github.sommrey.de/the-bears-den/2024/09/08/ch-284.html#task-2
+
+sub relative_sort ($list1, $list2) {
+    my $part1 = Tree::RB::XS->new(compare_fn => CMP_INT, track_recent => 1);
+    my $part2 = Tree::RB::XS->new(compare_fn => CMP_INT);
+    $part1->insert($_, 0) for @$list2;
+    ${\($part1->get($_) // $part2->get_or_add($_))}++ for @$list1;
+
+    [
+        map +($_->key) x $_->value,
+            $part1->iter_newer->next('*'),
+            $part2->iter->next('*')
+    ];
+}
+
+### Examples and tests
+
+sub run_tests {
+
+    is relative_sort([2, 3, 9, 3, 1, 4, 6, 7, 2, 8, 5],
+            [2, 1, 4, 3, 5, 6]), [2, 2, 1, 4, 3, 3, 5, 6, 7, 8, 9],
+            'example 1';
+    is relative_sort([3, 3, 4, 6, 2, 4, 2, 1, 3],
+            [1, 3, 2]),
+            [1, 3, 3, 3, 2, 2, 4, 4, 6],
+            'example 2';
+    is relative_sort([3, 0, 5, 0, 2, 1, 4, 1, 1],
+            [1, 0, 3, 2]),
+            [1, 1, 1, 0, 0, 3, 2, 4, 5],
+            'example 3';
+    done_testing;
+
+    exit;
+}