The Weekly Challenge

09. TASK #1: Beautiful Arrangement

HEADLINES

Welcome to the Week #300 of The Weekly Challenge.

Well done, Team PWC, for achieving another milestone. Getting to the Week #300 is a big achievement, in my humble opinion. Everybody need a big round of applause. Without your support and dedication, we wouldn’t have come so far. I see the side effects of holiday season, with less noise than usual. Well I don’t blame you. I hope and wish you all a great time with your loved ones. In the meantime, enjoy the Advent Calendar, some really magical one.

Advent Calendar 2024

Day 1: Leaping from Tree to Tree as They Float Down the Mighty Rivers of British Columbia by `Dave Jacoby`.

Day 2: Special Zeroes by `Jorg Sommrey`.

Day 3: Split the weakest by `Peter Campbell Smith`.

Day 4: Reverse Power by `Arne Sommer`.

Day 5: Odd Character / Most Frequent Word by `Laurent Rosenfeld`.

Day 6: Easy Pairs - Easy Merge by `Matthias Muth`.

Day 7: Smaller than Echelon by `Roger Bell_West`.

Day 8: Count Sumofvaluacula by `Adam Russell`.

Day 9: Target Index / Merge Items by `James Smith`.

Day 10: Unique Occurrences / Dictionary Rank by `Robbie Hatley`.

Day 11: Element Digit Sum / Dictionary Rank by `Simon Green`.

Day 12: Max Positive Negative / Count Equal Divisible by `Ali Moradi`.

Day 13: Don’t Sort It, Be Happy by `Bob Lied`.

Day 14: Greatest English Letter / Target Array by `W. Luis Mochan`.

Day 15: TDD for Good… strings by `Lance Wicks`.

Day 16: Complete Day / Maximum Frequency by `Ryan Thompson`.

Last 5 weeks mainstream contribution stats. Thank you Team PWC for your support and encouragements.


`Week`	`Perl`	`Raku`	`Blog`
`295`	45	20	24
`296`	49	19	16
`297`	44	20	23
`298`	35	18	21
`299`	37	13	10

Last 5 weeks guest contribution stats. Thank you each and every guest contributors for your time and efforts.


`Week`	`Guests`	`Contributions`	`Languages`
`295`	10	45	18
`296`	11	49	17
`297`	13	53	18
`298`	9	45	19
`299`	10	45	19

TOP 10 Guest Languages

Do you see your favourite language in the Top #10? If not then why not contribute regularly and make it to the top.

 1. Python     (3101)
 2. Rust       (812)
 3. Ruby       (753)
 4. Haskell    (729)
 5. Lua        (670)
 6. C          (589)
 7. C++        (571)
 8. JavaScript (516)
 9. Go         (440)
10. BQN        (397)

Blogs with Creative Title

1. Nothing But Words by Arne Sommer.

2. Search and Replace by Jorg Sommrey.

3. Words, words and more words by Peter Campbell Smith.

4. Words, Words, What Are Words? by Roger Bell_West.

5. The one about words by Simon Green.

GitHub Repository Stats

1. Commits: 41,556 (`+77`)

2. Pull Requests: 11,293 (`+24`)

3. Contributors: 254

4. Fork: 321

5. Stars: 178

With start of Week #268, we have a new sponsor Lance Wicks for the entire year 2024. Having said we are looking for more sponsors so that we can go back to weekly winner. If anyone interested please get in touch with us at perlweeklychallenge@yahoo.com. Thanks for your support in advance.

RECAP

Quick recap of The Weekly Challenge - 299 by Mohammad Sajid Anwar.

PERL REVIEW

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RAKU REVIEW

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CHART

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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 check out the guest contributions for the Week #299.

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

Task 1: Beautiful Arrangement

Submitted by: Mohammad Sajid Anwar

You are given a positive integer, $int.

Write a script to return the number of beautiful arrangements that you can construct.

A permutation of n integers, 1-indexed, is considered a beautiful arrangement
if for every i (1 <= i <= n) either of the following is true:

1) perm[i] is divisible by i
2) i is divisible by perm[i]

Example 1

Input: $n = 2
Output: 2

1st arrangement: [1, 2]
    perm[1] is divisible by i = 1
    perm[2] is divisible by i = 2
2nd arrangement: [2, 1]
    perm[1] is divisible by i = 1
    i=2 is divisible by perm[2] = 1

Example 2

Input: $n = 1
Output: 1

Example 3

Input: $n = 10
Output: 700

Task 2: Nested Array

Submitted by: Mohammad Sajid Anwar

You are given an array of integers, @ints of length n containing permutation of the numbers in the range [0, n - 1].

Write a script to build a set, set[i] = ints[i], ints[ints[i]], ints[ints[ints[i]]], ..., subjected to the following rules:

1. The first element in set[i] starts with the selection of elements ints[i].
2. The next element in set[i] should be ints[ints[i]], and then ints[ints[ints[i]]], and so on.
3. We stop adding right before a duplicate element occurs in set[i].

Return the longest length of a set set[i].

Example 1

Input: @ints = (5, 4, 0, 3, 1, 6, 2)
Output: 4

ints[0] = 5
ints[1] = 4
ints[2] = 0
ints[3] = 3
ints[4] = 1
ints[5] = 6
ints[6] = 2

One of the longest sets set[k]:
set[0] = {ints[0], ints[5], ints[6], ints[2]} = {5, 6, 2, 0}

Example 2

Input: @ints = (0, 1, 2)
Output: 1

Last date to submit the solution 23:59 (UK Time) Sunday 22^nd December 2024.