The Weekly Challenge - 162

Monday, Apr 25, 2022| Tags: Perl, Raku










09. TASK #1: ISBN-13

10. TASK #2: Wheatstone-Playfair


Time flies by so fast, it is unbelievable, we are now in the Week #162.

Let us all welcome new member, Rick Bychowski, from California and thank you for your first contributions in Raku.

We also had, Ryan Thompson, back in action. What a pleasant surprise. Not only he shared solutions in Perl but also shared blogs for Task #1 and Task #2. Those who don’t know, Ryan Thompson, he was our Perl Reviewer for a long time. Please checkout the interview with him, if you have time.

Colin Crain, our current Perl Reviewer, seems very busy this week as he could only do Task #1 in Perl. Usually he does both tasks in Perl and Raku with two blogs each for the task, every week. Having said, he did manage to review Perl solutions for the Week #157. Hopefully he would be back in action fully next week.

Last week was a special one for one more reason, Julien Fiegehenn, a very close friend of mine and work colleague (both of us work for Oleeo) shared solutions in Perl, after a long time.

As far as my contribution, I could only do Task #1 in Perl. I could have done the same in Raku but didn’t have any energy left. Ramadan is taking its toll. One more week left, it is likely next Monday we would celebrate Idd in England.

Last week, we couldn’t reach target but I am very happy to see consistent 30+ participants every week. Above all the quality of code is very high. Blogging is also on high, last week we had 20 blogs, thank you each and every member for the support and encouragement. Outside of the weekly challenge zone, I hardly see anyone blog about Perl and I am telling this being co-editor of Perl Weekly newsletter. So well done Team PWC for keeping the flame alive.

I just noticed my rank in the Leader Board slipped by 2 positions to 17th. I would blame two fellow members, Paulo Custodio and Duncan C. White for being consistent contributors. I really have to push harder now to maintain my position.

For those, who don’t know, we have Early Bird Club, where members get first peek of the upcoming challenges. If you are interested to join the club then please send me one line message to

Also I would like to request fellow members to suggest fun and interesting challenges if you know any. It would be a big help.

Good luck for this week challenge.

Blogs with Creative Title

1. Are Abecedarians from Abecedaria? by Adam Russell.

2. Panabecedarian Grams by Arne Sommer.

3. Pangram challenge: greed and Scrabble by Athanasius.

4. The Lazy Dog Had It Coming by Dave Jacoby.

5. Words and More Words by Roger Bell_West.

GitHub Repository Stats

1. Commits: 24,750 (+177)

2. Pull Requests: 5,989 (+41)

3. Contributors: 189 (+1)

4. Fork: 246 (+2)

5. Stars: 129 (+3)

Our solo sponsor Pete Sergeant has been a great support to keep us motivated. We are lucky that he agreed to continue the journey with us in the year 2022. I would like to personally thank Pete and his entire team for their generosity. It would be great if we could add few more to sponsor the prize money so that we could go back and declare weekly champions as we have done in the past. I hope and wish this will become possible in 2022. The amount doesn’t have to be huge. However, it would be nice to show off bunch of supporters. If an organisation comes forward and supports us then that would be the ultimate achievement.


Quick recap of The Weekly Challenge - 161 by Mohammad S Anwar.


Please check out Perl solutions review of The Weekly Challenge - 157 by Colin Crain.

If you missed any past reviews then please check out the collection.


If you missed any past reviews then please check out the collection.


Please take a look at the charts showing interesting data.

I would like to THANK every member of the team for their valuable suggestions. Please do share your experience with us.


Rick Bychowski, Raku expert from California, joined the Team PWC.

Please find out How to contribute?, if you have any doubts.

Please try the excellent tool EZPWC created by respected member Saif Ahmed of Team PWC.


Please checkout the guest contributions for the Week #161.

Please find past solutions by respected guests. Please share your creative solutions in other languages.

Task 1: ISBN-13

Submitted by: Mohammad S Anwar

Write a script to generate the check digit of given ISBN-13 code. Please refer wikipedia for more information.

ISBN-13 check digit for '978-0-306-40615-7' is 7.

Task 2: Wheatstone-Playfair

Submitted by: Roger Bell_West

Implement encryption and decryption using the Wheatstone-Playfair cipher.

(These combine I and J, and use X as padding.)

encrypt("playfair example", "hide the gold in the tree stump") = "bmodzbxdnabekudmuixmmouvif"

decrypt("perl and raku", "siderwrdulfipaarkcrw") = "thewexeklychallengex"

Last date to submit the solution 23:59 (UK Time) Sunday 1st May 2022.


If you have any suggestions or ideas then please do share with us.

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