Solution to task 1

1 files changed, 61 insertions, 0 deletions

diff --git a/challenge-255/jo-37/perl/ch-1.pl b/challenge-255/jo-37/perl/ch-1.pl
new file mode 100755
index 0000000000..1ecc01addb
--- /dev/null
+++ b/challenge-255/jo-37/perl/ch-1.pl
@@ -0,0 +1,61 @@
+#!/usr/bin/perl -s
+
+use v5.24;
+use Test2::V0;
+use experimental 'signatures';
+
+our ($tests, $examples);
+
+run_tests() if $tests || $examples;	# does not return
+
+die <<EOS unless @ARGV == 2;
+usage: $0 [-examples] [-tests] [S T]
+
+-examples
+    run the examples from the challenge
+ 
+-tests
+    run some tests
+
+S T
+    two strings
+
+EOS
+
+
+### Input and Output
+
+say "@{[char_diff(@ARGV)]}";
+
+
+### Implementation
+
+sub char_diff ($s, $t) {
+    my %count;
+    $count{$_}++ for split //, $t;
+    $count{$_}-- for split //, $s;
+    no warnings 'numeric';
+    map +($_) x $count{$_}, keys %count;
+}
+
+
+### Examples and tests
+
+sub run_tests {
+    SKIP: {
+        skip "examples" unless $examples;
+
+        is [char_diff('Perl', 'Preel')], ['e'], 'example 1';
+        is [char_diff('Weekly', 'Weeakly')], ['a'], 'example 2';
+        is [char_diff('Box', 'Boxy')], ['y'], 'example 3';
+    }
+
+    SKIP: {
+        skip "tests" unless $tests;
+
+        is [char_diff('abcde', 'ddd')], ['d', 'd'], 'more than one';
+	}
+
+    done_testing;
+    exit;
+}