From de2e9521aa5bd74001134daafb71386035b31a62 Mon Sep 17 00:00:00 2001
From: Andreas Mahnke <andreas.mahnke@leuphana.de>
Date: Mon, 21 Jul 2025 14:15:29 +0200
Subject: Challenge 331

---
 challenge-331/mahnkong/perl/ch-1.pl | 14 ++++++++++++++
 challenge-331/mahnkong/perl/ch-2.pl | 29 +++++++++++++++++++++++++++++
 2 files changed, 43 insertions(+)
 create mode 100644 challenge-331/mahnkong/perl/ch-1.pl
 create mode 100644 challenge-331/mahnkong/perl/ch-2.pl

diff --git a/challenge-331/mahnkong/perl/ch-1.pl b/challenge-331/mahnkong/perl/ch-1.pl
new file mode 100644
index 0000000000..9be87ad80e
--- /dev/null
+++ b/challenge-331/mahnkong/perl/ch-1.pl
@@ -0,0 +1,14 @@
+use strict;
+use warnings;
+use feature 'signatures';
+use Test::More 'no_plan';
+
+sub run($str) {
+    return ($str =~ /([a-z]+)[^a-z]*$/i) ? length($1) : 0;
+}
+
+is(run('The Weekly Challenge'), 9, "Example 1");
+is(run('   Hello   World    '), 5, "Example 2");
+is(run("Let's begin the fun"), 3, "Example 3");
+is(run(" 3 "), 0, "Example 4");
+is(run("  "), 0, "Example 5");
diff --git a/challenge-331/mahnkong/perl/ch-2.pl b/challenge-331/mahnkong/perl/ch-2.pl
new file mode 100644
index 0000000000..b117c0bfa0
--- /dev/null
+++ b/challenge-331/mahnkong/perl/ch-2.pl
@@ -0,0 +1,29 @@
+use strict;
+use warnings;
+use feature 'signatures';
+use Test::More 'no_plan';
+
+sub check_buddy_string($ref, $compare_string, $i, $c_index) {
+    my @s = @{$ref};
+    my $c = $s[$i];
+    my $o = $s[$c_index];
+    $s[$i] = $o;
+    $s[$c_index] = $c;
+    return 1 if ($compare_string eq join('', @s));
+}
+
+sub run($str1, $str2) {
+    return 0 if (length($str1) != length($str2)) || length($str1) == 0;
+
+    my @str2 = split//, $str2;
+    for (my $i = 0; $i <= $#str2; $i++) {
+        return 1 if $i > 0 && check_buddy_string(\@str2, $str1, $i, $i-1);
+        return 1 if $i < $#str2 && check_buddy_string(\@str2, $str1, $i, $i+1);
+    }
+    return 0;
+}
+
+is(run("fuck", "fcuk"), 1, "Example 1");
+is(run("love", "love"), 0, "Example 2");
+is(run("fodo", "food"), 1, "Example 3");
+is(run("feed", "feed"), 1, "Example 4");
-- 
cgit