TABLE OF CONTENTS

  1. HEADLINES

  2. SPONSOR

  3. RECAP

  4. PERL REVIEW

  5. RAKU REVIEW

  6. CHART

  7. NEW MEMBERS

  8. GUESTS

  9. TASK #1: Min Abs Diff

10. TASK #2: Shift Grid

HEADLINES

Welcome to the Week #354 of The Weekly Challenge.

Let us all welcome our new member, Marc Perry, to Team PWC. Thank you, Marc, for your first contributions in Perl.

This is the final week of 2025. Time flies.

Very soon, we will welcome new year - 2026.

Enjoy the last few days of the holiday season.

As you all know, Lance Wicks, has been the sole sponsor of our monthly prize pot for two consecutive years, ending in December 2025. I have sent him a gentle reminder to see if he is willing to continue sponsoring in 2026. I will update the team as soon as I hear back from him.

In the meantime, if anyone else would like to support us, that would be greatly appreciated.

Below is my contributions to the Task #1 of Week #353.

Perl: source code

sub max_word {
    my @w = map { scalar split } @{$_[0]};
    return 0+(@w ? (sort {$b <=> $a} @w)[0] : 0);
}

Raku: source code

sub max_word(@sentences) {
    my @w = @sentences.map: { $_.words.elems };
    return @w ?? @w.sort.reverse[0] !! 0;
}

Python: source code

def max_word(sentences):
    if not sentences:
        return 0
    return max(len(sentence.split()) for sentence in sentences)

Thank you Team PWC, once again.

Happy Hacking!!

Advent Calendar 2025

So finally we have completed the Advent Calendar 2025, thanks to all the contributors.

Day  1: 3-digits Even/Delete and Earn by Ali Moradi.

Day  2: Not Modified by Dave Jacoby.

Day  3: Alien Primes by Jorg Sommrey.

Day  4: Odd game by Peter Campbell Smith.

Day  5: Don’t Get Trapped by Matthias Muth.

Day  6: Exclusive or Common by Arne Sommer.

Day  7: Perl and Raku mainly by Luca Ferrari.

Day  8: Arrays Intersection/Sort Odd Even by Jaldhar H. Vyas.

Day  9: Lower the Sum by Roger Bell_West.

Day 10: Minimum Time/Balls and Boxes by W. Luis Mochan.

Day 11: Reverse Broken Keys for Letters by Adam Russell.

Day 12: Equal Strings/Sort Column by Robbie Hatley.

Day 13: Sub circular by Simon Green.

Day 14: Reverse Equals by Bob Lied.

Day 15: Count the Minimum Common Word by Packy Anderson.

Day 16: 2D Array/Total XOR by Yitzchak Scott-Thoennes.

Day 17: Day of the Year and Decompressed List by Walt Mankowski.

Day 18: Max Diff/Peak Point by Torgny Lyon.

Day 19: Brken Keybards and Reverse Prefixes by Ryan Thompson.

Day 20: Add to Array Form/Build Target from Source Subarrays by Vinod Kumar K.

Day 21: Format Date by Feng Chang.

Day 22: Lost Connections and Making Changes by David Ferrone.

Day 23: Discs and Spheres by Kaushik Tunuguntla.

Day 24: Strong Password/Valid Number by Peter Pentchev.

Day 25: Merry Christmas by Mohammad Sajid Anwar.

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

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

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     (3884)
 2. Rust       (1076)
 3. Ruby       (858)
 4. Haskell    (845)
 5. Lua        (816)
 6. C++        (678)
 7. JavaScript (610)
 8. Go         (606)
 9. C          (596)
10. BQN        (495)

Blogs with Creative Title

1. Max Validate by Arne Sommer.

2. To each (array) his own by Bob Lied.

3. waiting for Santa… by Luca Ferrari.

4. Validate to the Max by Matthias Muth.

5. Ok, swing code… SWING! by Packy Anderson.

6. Words and shopping by Peter Campbell Smith.

7. Max Validation by Roger Bell_West.

8. Validating Words by Simon Green.

GitHub Repository Stats

1. Commits: 46,975 (+138)

2. Pull Requests: 13,229 (+49)

3. Contributors: 270 (+1)

4. Fork: 344

5. Stars: 206 (+2)

SPONSOR

With start of Week #268, we have a new sponsor Lance Wicks until the end of year 2025. 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 - 353 by Mohammad Sajid Anwar.

PERL REVIEW

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

Marc Perry, Perl hacker from Los Angeles joined 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.

GUESTS

Please check out the guest contributions for the Week #353.

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

Task 1: Min Abs Diff

Submitted by: Mohammad Sajid Anwar

You are given an array of distinct integers.

Write a script to find all pairs of elements with the minimum absolute difference.

Rules (a,b):
1: a, b are from the given array.
2: a < b
3: b - a = min abs diff any two elements in the given array

Example 1

Input: @ints= (4, 2, 1, 3)
Output: [1, 2], [2, 3], [3, 4]

Example 2

Input: @ints = (10, 100, 20, 30)
Output: [10, 20], [20, 30]

Example 3

Input: @ints = (-5, -2, 0, 3)
Output: [-2, 0]

Example 4

Input: @ints = (8, 1, 15, 3)
Output: [1, 3]

Example 5

Input: @ints = (12, 5, 9, 1, 15)
Output: [9, 12], [12, 15]

Task 2: Shift Grid

Submitted by: Mohammad Sajid Anwar

You are given m x n matrix and an integer, $k > 0.

Write a script to shift the given matrix $k times.

Each shift follow the rules:

Rule 1:
Element at grid[i][j] moves to grid[i][j + 1]
This means every element moves one step to the right within its row.

Rule 2:
Element at grid[i][n - 1] moves to grid[i + 1][0]
This handles the last column: elements in the last column of row i wrap to the first column of the next row (i+1).

Rule 3:
Element at grid[m - 1][n - 1] moves to grid[0][0]
This is the bottom-right corner: it wraps to the top-left corner.

Example 1

Input: @matrix = ([1, 2, 3],
                  [4, 5, 6],
                  [7, 8, 9],)
       $k = 1
Output: ([9, 1, 2],
         [3, 4, 5],
         [6, 7, 8],)

Rule 1: grid[i][j] -> grid[i][j+1] for j < n-1.

We take elements from the original grid at (i, j) and put them into new_grid[i][j+1].

From original:

(0,0): 1 -> new_grid[0][1] = 1
(0,1): 2 -> new_grid[0][2] = 2
(1,0): 4 -> new_grid[1][1] = 4
(1,1): 5 -> new_grid[1][2] = 5
(2,0): 7 -> new_grid[2][1] = 7
(2,1): 8 -> new_grid[2][2] = 8

New grid looks after Rule 1:

([?, 1, 2],
 [?, 4, 5],
 [?, 7, 8],)

Rule 2: grid[i][n-1] -> grid[i+1][0] for i < m-1.

Elements from original last column (except last row) go to next row's first column.

From original:

(0,2): 3 -> new_grid[1][0] = 3
(1,2): 6 -> new_grid[2][0] = 6

Now new grid after Rules 1 + 2:

([?, 1, 2],
 [3, 4, 5],
 [6, 7, 8],)

Rule 3: grid[m-1][n-1] -> grid[0][0].

Original (2,2): 9 -> new_grid[0][0] = 9.

Now new_grid is complete:

([9, 1, 2],
 [3, 4, 5],
 [6, 7, 8],)

Example 2

Input: @matrix = ([10, 20],
                  [30, 40],)
       $k = 1
Output: ([40, 10],
         [20, 30],)

Rule 1 (move right in same row if not last column):

(0,0): 10 -> new[0][1] = 10
(1,0): 30 -> new[1][1] = 30

After Rule 1:

([?, 10],
 [?, 30],)

Rule 2 (last col -> next row’s first col, except last row):

(0,1): 20 -> new[1][0] = 20

After Rule 2:

([?,  10],
 [20, 30],)

Rule 3 (bottom-right to top-left):

(1,1): 40 -> new[0][0] = 40

After Rule 3:

([40, 10],
 [20, 30],)

Example 3

Input: @matrix = ([1, 2],
                  [3, 4],
                  [5, 6],)
      $k = 1
Output: ([6, 1],
         [2, 3],
         [4, 5],)

Rule 1:
(0,0): 1 -> new[0][1] = 1
(1,0): 3 -> new[1][1] = 3
(2,0): 5 -> new[2][1] = 5

After Rule 1:
( [?, 1],
  [?, 3],
  [?, 5],)

Rule 2:
(0,1): 2 -> new[1][0] = 2
(1,1): 4 -> new[2][0] = 4

After Rule 2:
([?, 1],
 [2, 3],
 [4, 5],)

Rule 3:
(2,1): 6 -> new[0][0] = 6

After Rule 3:
([6, 1],
 [2, 3],
 [4, 5],)

Example 4

Input: @matrix = ([1, 2, 3],
                  [4, 5, 6],)
       $k = 5
Output: ([2, 3, 4],
         [5, 6, 1],)

Shift 1

Rule 1
1 -> (0,1)
2 -> (0,2)
4 -> (1,1)
5 -> (1,2)

Rule 2
3 -> (1,0) (last column of row 0)

Rule 3
6 -> (0,0) (bottom-right corner)

Result
[6, 1, 2]
[3, 4, 5]

----------------------------

Shift 2

Starting from the previous matrix:

[6, 1, 2]
[3, 4, 5]

Rule 1
6 -> (0,1)
1 -> (0,2)
3 -> (1,1)
4 -> (1,2)

Rule 2
2 -> (1,0)

Rule 3
5 -> (0,0)

Result
[5, 6, 1]
[2, 3, 4]

----------------------------

Shift 3

[5, 6, 1]
[2, 3, 4]

Rule 2: 1 -> (1,0)
Rule 3: 4 -> (0,0)

Others follow Rule 1

Result
[4, 5, 6]
[1, 2, 3]

----------------------------

Shift 4

[4, 5, 6]
[1, 2, 3]

Result
[3, 4, 5]
[6, 1, 2]

----------------------------

Shift 5
[3, 4, 5]
[6, 1, 2]

Result
[2, 3, 4]
[5, 6, 1]

Final Output (after k = 5 shifts)
([2, 3, 4],
 [5, 6, 1])

Example 5

Input: @matrix = ([1, 2, 3, 4])
       $k = 1
Output: ([4, 1, 2, 3])

Rule 1:
(0,0): 1 -> new[0][1] = 1
(0,1): 2 -> new[0][2] = 2
(0,2): 3 -> new[0][3] = 3

After Rule 1:
([?, 1, 2, 3])

Rule 2:
(0,3): 4 -> new[1][0] ??

Wait — but i=0, n-1=3, next row i+1=1 doesn’t exist (m=1).
So this is actually a special case where Rule 2 should not apply.
because m=1, so (0,3) goes by Rule 3 actually.

The rules say:
grid[i][j]     -> grid[i][j+1] for j < n-1.
grid[i][n-1]   -> grid[i+1][0] for i < m-1.
grid[m-1][n-1] -> grid[0][0].

For m = 1:
Elements (0,0),(0,1),(0,2) follow Rule 1 -> (0,1),(0,2),(0,3).
Element (0,3) is (m-1, n-1), so follows Rule 3 -> (0,0).

Actually, that means after Rule 1:
We put 1,2,3 in positions 1,2,3, leaving position 0 empty.
Then Rule 3 puts 4 in position 0.

So final directly:
[4, 1, 2, 3]

Last date to submit the solution 23:59 (UK Time) Sunday 4th January 2026.