Solution to task 1

1 files changed, 79 insertions, 0 deletions

diff --git a/challenge-289/jo-37/perl/ch-1.pl b/challenge-289/jo-37/perl/ch-1.pl
new file mode 100755
index 0000000000..0d941f4b6e
--- /dev/null
+++ b/challenge-289/jo-37/perl/ch-1.pl
@@ -0,0 +1,79 @@
+#!/usr/bin/perl -s
+
+use v5.24;
+use Test2::V0;
+use warnings FATAL => 'all';
+use Data::Dump qw(dd pp);
+use experimental 'signatures';
+
+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 integers
+
+EOS
+
+
+### Input and Output
+
+say third_max(@ARGV);
+
+
+### Implementation
+#
+# For details see:
+# https://github.sommrey.de/the-bears-den/2024/10/04/ch-289.html#task-1
+
+
+sub third_max {
+    my @max = ('-inf') x 3;
+    n: for my $n (@_) {
+        i: for my $i (0 .. 2) {
+            if ($n == $max[$i]) {
+                next n;
+            } elsif ($n > $max[$i]) {
+                splice(@max, $i, 0, $n);
+                $#max = 2;
+                last i;
+            }
+        }
+    }
+
+    $max[2] > '-inf' ? $max[2] : $max[0];
+}
+
+
+### Examples and tests
+
+sub run_tests {
+    SKIP: {
+        skip "examples" unless $examples;
+
+        is third_max(5, 6, 4, 1), 4, 'example 1';
+        is third_max(4, 5), 5, 'example 2';
+        is third_max(1, 2, 2, 3), 1, 'example 3';
+    }
+
+    SKIP: {
+        skip "tests" unless $tests;
+
+        is third_max(1, 1, 2, 2, 3, 3, 4, 4), 2, 'all doubles';
+        is third_max(3, 3, 4, 4), 4, 'no third';
+
+
+	}
+
+    done_testing;
+    exit;
+}