Solution to task 1

1 files changed, 64 insertions, 0 deletions

diff --git a/challenge-210/jo-37/perl/ch-1.pl b/challenge-210/jo-37/perl/ch-1.pl
new file mode 100755
index 0000000000..8a8aef7f2e
--- /dev/null
+++ b/challenge-210/jo-37/perl/ch-1.pl
@@ -0,0 +1,64 @@
+#!/usr/bin/perl -s
+
+use v5.16;
+use Test2::V0;
+use List::Util qw(sum max);
+use List::UtilsBy qw(count_by);
+
+our ($tests, $examples);
+
+run_tests() if $tests || $examples;	# does not return
+
+die <<EOS unless @ARGV;
+usage: $0 [-examples] [-tests] [--] [N...]
+
+-examples
+    run the examples from the challenge
+ 
+-tests
+    run some tests
+
+N...
+    list of numbers
+
+EOS
+
+
+### Input and Output
+
+say kill_and_win(@ARGV);
+
+
+### Implementation
+
+# Brute force implementation.
+
+sub kill_and_win {
+    # Create a map from values to their frequencies.
+	my %freq = count_by {$_} @_;
+    # Find the maximum over three consectutive values.
+    max map {
+        sum map {$_ * ($freq{$_} // 0)} $_ - 1, $_, $_ + 1
+    } keys %freq;
+}
+
+
+### Examples and tests
+
+sub run_tests {
+    SKIP: {
+        skip "examples" unless $examples;
+
+        is kill_and_win(2, 3, 1), 6, 'example 1';
+        is kill_and_win(1, 1, 2, 2, 2, 3), 11, 'example 2';
+    }
+
+    SKIP: {
+        skip "tests" unless $tests;
+
+        is kill_and_win(1, 1, 2, 2, 3, 3, 13), 13, 'single large value';
+	}
+
+    done_testing;
+    exit;
+}