3 files changed, 186 insertions, 0 deletions
diff --git a/challenge-320/jo-37/blog.txt b/challenge-320/jo-37/blog.txt
new file mode 100644
index 0000000000..09ad218a47
--- /dev/null
+++ b/challenge-320/jo-37/blog.txt
@@ -0,0 +1 @@
+https://github.sommrey.de/the-bears-den/2025/05/09/ch-320.html
diff --git a/challenge-320/jo-37/perl/ch-1.pl b/challenge-320/jo-37/perl/ch-1.pl
new file mode 100755
index 0000000000..76527f952f
--- /dev/null
+++ b/challenge-320/jo-37/perl/ch-1.pl
@@ -0,0 +1,93 @@
+#!/usr/bin/perl
+
+use v5.26;
+use Test2::V0 qw(!float -no_srand);
+use Test2::Tools::Subtest 'subtest_streamed';
+use Getopt::Long;
+use experimental 'signatures';
+
+use PDL;
+
+### Options and Arguments
+
+my ($tests, $examples, $verbose);
+GetOptions(
+    'examples!' => \$examples,
+    'tests!'    => \$tests,
+    'verbose!'  => \$verbose,
+) or usage();
+
+run_tests($examples, $tests);	# tests do not return
+
+usage() unless @ARGV;
+
+sub usage {
+    die <<~EOS;
+    $0 - maximum count
+
+    usage: $0 [-examples] [-tests] [--] [I...]
+
+    -examples
+        run the examples from the challenge
+     
+    -tests
+        run some tests
+
+    I...
+        list of integers
+
+    EOS
+}
+
+
+### Input and Output
+
+say max_count(@ARGV);
+
+
+### Implementation
+#
+# For details see:
+# https://github.sommrey.de/the-bears-den/2025/05/09/ch-320.html#task-1
+
+
+sub max_count {
+    my $s = long(@_)->clip(-1, 1);
+    (sum(abs $s) + abs(sum $s)) / 2;
+}
+
+
+### Examples and Tests
+
+sub run_tests ($examples, $tests) {
+    return unless $examples || $tests;
+
+    state sub run_example ($args, $expected, $name) {
+        my $result = max_count(@$args);
+        is $result, $expected,
+            "$name: (@$args) -> $expected";
+    }
+
+    plan 2;
+
+    $examples ? subtest_streamed(examples => sub {
+        my @examples = (
+            [[-3, -2, -1, 1, 2, 3], 3, 'example 1'],
+            [[-2, -1, 0, 0, 1], 2, 'example 2'],
+            [[1, 2, 3, 4], 4, 'example 3'],
+        );
+        plan scalar @examples;
+        for (@examples) {
+            run_example @$_;
+        }
+    }) : pass 'skip examples';
+
+    $tests ? subtest_streamed(tests => sub {
+        plan 3;
+        is max_count(0, 0, 0), 0, 'zeroes only';
+        is max_count(-1, -2, -3), 3, 'negative only';
+        is max_count(0 .. 99, -99 .. 0), 99, 'ninty nine';
+    }) : pass 'skip tests';
+
+    exit;
+}
diff --git a/challenge-320/jo-37/perl/ch-2.pl b/challenge-320/jo-37/perl/ch-2.pl
new file mode 100755
index 0000000000..7ad04bbbc6
--- /dev/null
+++ b/challenge-320/jo-37/perl/ch-2.pl
@@ -0,0 +1,92 @@
+#!/usr/bin/perl
+
+use v5.26;
+use Test2::V0 -no_srand;
+use Test2::Tools::Subtest 'subtest_streamed';
+use Getopt::Long;
+use experimental 'signatures';
+
+use Math::Prime::Util qw(vecsum todigits);
+
+
+### Options and Arguments
+
+my ($tests, $examples, $verbose);
+GetOptions(
+    'examples!' => \$examples,
+    'tests!'    => \$tests,
+    'verbose!'  => \$verbose,
+) or usage();
+
+run_tests($examples, $tests);	# tests do not return
+
+usage() unless @ARGV;
+
+sub usage {
+    die <<~EOS;
+    $0 - sum difference
+
+    usage: $0 [-examples] [-tests] [N...]
+
+    -examples
+        run the examples from the challenge
+     
+    -tests
+        run some tests
+
+    N...
+        list of positive integers
+
+    EOS
+}
+
+
+### Input and Output
+
+say sum_diff(@ARGV);
+
+
+### Implementation
+#
+# For details see:
+# https://github.sommrey.de/the-bears-den/2025/05/09/ch-320.html#task-2
+
+use constant BASE => 10;
+
+sub sum_diff {
+    vecsum(@_) - vecsum map todigits($_, BASE), @_;
+}
+
+
+### Examples and Tests
+
+sub run_tests ($examples, $tests) {
+    return unless $examples || $tests;
+
+    state sub run_example ($args, $expected, $name) {
+        my $result = sum_diff(@$args);
+        is $result, $expected,
+            "$name: (@$args) -> $expected";
+    }
+
+    plan 2;
+
+    $examples ? subtest_streamed(examples => sub {
+        my @examples = (
+            [[1, 23, 4, 5], 18, 'example 1'],
+            [[1, 2, 3, 4, 5], 0, 'example 2'],
+            [[1, 2, 34], 27, 'example 3'],
+        );
+        plan scalar @examples;
+        for (@examples) {
+            run_example @$_;
+        }
+    }) : pass 'skip examples';
+
+    $tests ? subtest_streamed(tests => sub {
+        plan 1;
+        pass 'no tests';
+    }) : pass 'skip tests';
+
+    exit;
+}