Solution to task 2

1 files changed, 68 insertions, 0 deletions

diff --git a/challenge-276/jo-37/perl/ch-2.pl b/challenge-276/jo-37/perl/ch-2.pl
new file mode 100755
index 0000000000..40c1c23c22
--- /dev/null
+++ b/challenge-276/jo-37/perl/ch-2.pl
@@ -0,0 +1,68 @@
+#!/usr/bin/perl -s
+
+use v5.24;
+use Test2::V0;
+use List::Util 'reduce';
+
+our ($tests, $examples);
+
+run_tests() if $tests || $examples;	# does not return
+
+die <<EOS unless @ARGV;
+usage: $0 [-examples] [-tests] [I...]
+
+-examples
+    run the examples from the challenge
+ 
+-tests
+    run some tests
+
+I...
+    list of items
+
+EOS
+
+
+### Input and Output
+
+say max_freq(@ARGV);
+
+
+### Implementation
+#
+# For details see:
+# https://github.sommrey.de/the-bears-den/2024/07/05/ch-276.html#task-2
+
+
+sub max_freq {
+    my ($maxfreq, %freq) = 0;
+
+    reduce {
+        &{ ( sub {$a + $maxfreq},
+             sub {$maxfreq = $freq{$b}},
+             sub {$a}
+           )[++$freq{$b} <=> $maxfreq]
+        }()
+    } 0, @_;
+}
+
+
+### Examples and tests
+
+sub run_tests {
+    SKIP: {
+        skip "examples" unless $examples;
+
+        is max_freq(1, 2, 2, 4, 1, 5), 4, 'example 1';
+        is max_freq(1, 2, 3, 4, 5), 5, 'example 2';
+    }
+
+    SKIP: {
+        skip "tests" unless $tests;
+
+        is max_freq(qw(a b a b c d c d e f e f e c a)), 9, 'non-numbers'
+	}
+
+    done_testing;
+    exit;
+}