Solution to task 2

1 files changed, 63 insertions, 0 deletions

diff --git a/challenge-235/jo-37/perl/ch-2.pl b/challenge-235/jo-37/perl/ch-2.pl
new file mode 100755
index 0000000000..6075cac684
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+++ b/challenge-235/jo-37/perl/ch-2.pl
@@ -0,0 +1,63 @@
+#!/usr/bin/perl -s
+
+use v5.24;
+use Test2::V0 '!float';
+use PDL;
+
+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 "(@{dup_zeroes(@ARGV)})";
+
+
+### Implementation
+
+# There's almost no need to comment this implementation as it literally
+# follows the task: Count sequential occurrences of every number, double
+# all zeroes' occurrences and trim the result to the original size.
+
+sub dup_zeroes {
+	my $n = long @_;
+    my ($l, $v) = rle $n;
+    $l->where($v == 0) *= 2;
+    rld($l, $v)->reshape($n->dims)->unpdl;
+}
+
+
+### Examples and tests
+
+sub run_tests {
+    SKIP: {
+        skip "examples" unless $examples;
+        
+        is dup_zeroes(1, 0, 2, 3, 0, 4, 5, 0),
+            [1, 0, 0, 2, 3, 0, 0, 4], 'example 1';
+        is dup_zeroes(1, 2, 3), [1, 2, 3], 'example 2';
+        is dup_zeroes(0, 3, 0, 4, 5), [0, 0, 3, 0, 0], 'example 3';
+    }
+
+    SKIP: {
+        skip "tests" unless $tests;
+	}
+
+    done_testing;
+    exit;
+}