Solution to task 1

1 files changed, 57 insertions, 0 deletions

diff --git a/challenge-256/jo-37/perl/ch-1.pl b/challenge-256/jo-37/perl/ch-1.pl
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+++ b/challenge-256/jo-37/perl/ch-1.pl
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+#!/usr/bin/perl -s
+
+use v5.24;
+use Test2::V0;
+
+our ($tests, $examples);
+
+run_tests() if $tests || $examples;	# does not return
+
+die <<EOS unless @ARGV;
+usage: $0 [-examples] [-tests] [W...]
+
+-examples
+    run the examples from the challenge
+ 
+-tests
+    run some tests
+
+W...
+    list of words
+
+EOS
+
+
+### Input and Output
+
+say maximum_pairs(@ARGV);
+
+
+### Implementation
+
+sub maximum_pairs {
+    (\my %words)->@{@_} = map scalar reverse, @_;
+
+    delete @words{grep $_ eq $words{$_}, keys %words};
+    (grep defined, delete @words{values %words}) / 2; 
+}
+
+
+### Examples and tests
+
+sub run_tests {
+    SKIP: {
+        skip "examples" unless $examples;
+
+        is maximum_pairs("ab", "de", "ed", "bc"), 1, 'example 1';
+        is maximum_pairs("aa", "ba", "cd", "ed"), 0, 'example 2';
+        is maximum_pairs("uv", "qp", "st", "vu", "mn", "pq"), 2, 'example 3';
+    }
+
+    SKIP: {
+        skip "tests" unless $tests;
+	}
+
+    done_testing;
+    exit;
+}