Solution to task 1

1 files changed, 62 insertions, 0 deletions

diff --git a/challenge-285/jo-37/perl/ch-1.pl b/challenge-285/jo-37/perl/ch-1.pl
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+++ b/challenge-285/jo-37/perl/ch-1.pl
@@ -0,0 +1,62 @@
+#!/usr/bin/perl -s
+
+use v5.24;
+use Test2::V0;
+use Graph::Directed;
+
+our ($tests, $examples);
+
+run_tests() if $tests || $examples;	# does not return
+
+die <<EOS unless @ARGV;
+usage: $0 [-examples] [-tests] [ROUTE...]
+
+-examples
+    run the examples from the challenge
+ 
+-tests
+    run some tests
+
+ROUTE...
+   routes given as origin-destination, e.g A-B 
+
+EOS
+
+
+### Input and Output
+
+say for no_connection(map [split qr/-/, $_], @ARGV);
+
+
+### Implementation
+#
+# For details see:
+# https://github.sommrey.de/the-bears-den/2024/09/06/ch-285.html#task-1
+
+
+sub no_connection {
+    Graph::Directed->new(edges => \@_)->sink_vertices;
+}
+
+
+### Examples and tests
+
+sub run_tests {
+    SKIP: {
+        skip "examples" unless $examples;
+
+        is [no_connection(["B","C"], ["D","B"], ["C","A"])], ["A"],
+            "example 1";
+        is [no_connection(["A","Z"])], ["Z"],
+            "example 2";
+    }
+
+    SKIP: {
+        skip "tests" unless $tests;
+
+        is [no_connection(["A", "B"], ["B", "C"], ["C", "A"])], [], 'cycle';
+	}
+
+    done_testing;
+    exit;
+}