Solution to task 1

1 files changed, 63 insertions, 0 deletions

diff --git a/challenge-206/jo-37/perl/ch-1.pl b/challenge-206/jo-37/perl/ch-1.pl
new file mode 100755
index 0000000000..923a8f1088
--- /dev/null
+++ b/challenge-206/jo-37/perl/ch-1.pl
@@ -0,0 +1,63 @@
+#!/usr/bin/perl -s
+
+use v5.16;
+use Test2::V0 '!float';
+use PDL;
+
+our ($tests, $examples);
+
+run_tests() if $tests || $examples;	# does not return
+
+die <<EOS unless @ARGV > 1;
+usage: $0 [-examples] [-tests] [H1:M1 H2:M2...]
+
+-examples
+    run the examples from the challenge
+ 
+-tests
+    run some tests
+
+H1:M1 H2:M2...
+    list of times in 24h-format HH:MM.
+
+EOS
+
+
+### Input and Output
+
+say shortest_time(@ARGV);
+
+
+### Implementation
+
+sub shortest_time {
+    # Parse times, calculate minutes, convert to "long" piddle and sort.
+	my $times = long(map {/^(\d{2}):(\d{2})$/ ? 60 * $1 + $2 : ()} @_)->qsort;
+    # Take the minimum over the difference of cyclic consecutive time
+    # pairs modulo one day.
+    min +($times->rotate(-1) - $times) % 1440;
+
+
+}
+
+
+### Examples and tests
+
+sub run_tests {
+    SKIP: {
+        skip "examples" unless $examples;
+
+        is shortest_time("00:00", "23:55", "20:00"), 5, 'example 1';
+        is shortest_time("01:01", "00:50", "00:57"), 4, 'example 2';
+        is shortest_time("10:10", "09:30", "09:00", "09:55"), 15, 'example 3';
+    }
+
+    SKIP: {
+        skip "tests" unless $tests;
+
+        is shortest_time(qw(23:00 18:00 01:00)), 120, 'carry minimum over';
+	}
+
+    done_testing;
+    exit;
+}