The Weekly Challenge

09. TASK #1: Missing Permutation

HEADLINES

Welcome to yet another week full of factorials left right center. The magic of factorials did the trick. For the first time in the history of weekly challenge, we have received more guest contributions than the regular contributions. Two contributors stand out in the crowd, although every contributor is special. Abigail and Laurent Rosenfeld, you must have guessed it by now. I would like to thank Laurent for being one of the few who have been with us from day one. I would also like to thank him for the final push to get over the magic target.

While I am talking about guest contributions, I would like to thank Bruce Gray for introducing a new guest language WebAssembly and shared his contributions.

At the time of releasing the weekly challenge, we received 106 guest contributions as compared to 90 regular contributions. Still the regular contributions beat the last week number i.e. 78 regular contributions. I hope we can reverse the number this week.

As for my own contributions, I could only do Perl this week because of lack of time. Having said, I would definitely try the challenge in Raku and Python if time permits this week.

All the best for the weekly challenge, I hope you like it. Please do share your suggestions for the upcoming weekly challenges.

Blogs with Creative Title

1. Finding the Factorials and Factorions That Are Left by Adam Russell.

2. Challenge 153 Task #1 - Factorials left, factorials right, factorials everywhere! by Alexander Pankoff.

3. Challenge 153 Task #2 - Even more factorials and what the fuck are factorions? by Alexander Pankoff.

4. Just the Fact with Raku by Arne Sommer.

5. Facts Left on the Table by the Front Door by Colin Crain.

6. Factory People in a Factory World by Colin Crain.

7. Luck is not a Factor!: Weekly Challenge #153 by Dave Jacoby

8. Perl Weekly Challenge 153: take it easy by Luca Ferrari.

9. !Task one is quite easy. Factorions are quite rare. by Peter Campbell Smith.

10. The Weekly Challenge 153: Factoriality by Roger Bell_West.

GitHub Repository Stats

1. Commits: 23,536 (+117)

2. Pull Requests: 5,708 (+31)

3. Contributors: 187 (+1)

4. Fork: 243

5. Stars: 121 (+2)

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 2021. 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 2021. 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.

RECAP

Quick recap of “The Weekly Challenge - 153” by Mohammad S Anwar.

PERL REVIEW

Please check out Perl solutions review of the “The Weekly Challenge - 149” by Colin Crain.

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

RAKU REVIEW

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

CHART

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.

NEW MEMBERS

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.

GUESTS

Please checkout the guest contributions for the Week #153.

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

TASK #1 › Missing Permutation

Submitted by: Mohammad S Anwar

You are given possible permutations of the string 'PERL'.

PELR, PREL, PERL, PRLE, PLER, PLRE, EPRL, EPLR, ERPL,
ERLP, ELPR, ELRP, RPEL, RPLE, REPL, RELP, RLPE, RLEP,
LPER, LPRE, LEPR, LRPE, LREP

Write a script to find any permutations missing from the list.

TASK #2 › Padovan Prime

Submitted by: Mohammad S Anwar

A Padovan Prime is a Padovan Number that’s also prime.

In number theory, the Padovan sequence is the sequence of integers P(n) defined by the initial values.

P(0) = P(1) = P(2) = 1

and then followed by

P(n) = P(n-2) + P(n-3)

First few Padovan Numbers are as below:

1, 1, 1, 2, 2, 3, 4, 5, 7, 9, 12, 16, 21, 28, 37, ...

Write a script to compute first 10 distinct Padovan Primes.

Expected Output

2, 3, 5, 7, 37, 151, 3329, 23833, 13091204281, 3093215881333057

Last date to submit the solution 23:59 (UK Time) Sunday 6th March 2022.