The Weekly Challenge: 383

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: Similar List

10. TASK #2: Nearest RGB

HEADLINES

Welcome to the Week #383 of The Weekly Challenge.

Apology for late arrival of this week challenge. The week #382 turned out to be least popular week of 2026. I hope to see more energy this week.

I had really tough time to solve the task #1. It was supposed to be easy one but actually it was not something you can do in your head easily. I am not happy with my contribution either. I just did it anyway, not to break the continuity otherwise I would be gone for a long time.

We have a new guest language, Maxima, added to the list, thanks Jorg Sommrey for your contribution in Maxima. We now have 125 guest languages altogether.

We have a change in rankings in guest languages. Ruby is now rank #4 and pushed Haskell to rank #5. Lua is catching up with rank #6.

Below is my contributions to the Task #1 of Week #382.

Perl: source code

sub gen_all_circles {
    my $n = shift;

    my %squares = map { $_*$_ => 1 } 1 .. int(sqrt(2*$n));

    my @all_solutions;
    my @path = (1);
    my @used;
    $used[1] = 1;

    my $dfs;
    $dfs = sub {
        if (@path == $n) {
            if ($squares{$path[-1] + $path[0]}) {
                push @all_solutions, [@path];
            }
            return;
        }

        for my $next (2 .. $n) {
            next if $used[$next] || !$squares{$path[-1] + $next};

            $used[$next] = 1;
            push @path, $next;

            $dfs->();

            $used[$next] = 0;
            pop @path;
        }
    };

    $dfs->();
    return @all_solutions;
}

Raku: source code

sub dfs() {
    if @path.elems == $N {
        return %squares{@path[*-1] + @path[0]} ?? True !! False;
    }

    my $last = @path[*-1];
    for 2 .. $N -> $next {
        next if @used[$next];
        next unless %squares{$last + $next};

        @used[$next] = True;
        @path.push($next);

        return True if dfs();

        @path.pop;
        @used[$next] = False;
    }

    return False;
}

Python: source code

def gen_all_circles(n):
    limit = int(math.sqrt(2 * n))
    squares = {i * i: 1 for i in range(1, limit + 1)}

    all_solutions = []
    path = [1]
    used = [0] * (n + 1)
    used[1] = 1

    def dfs():
        if len(path) == n:
            if (path[-1] + path[0]) in squares:
                all_solutions.append(list(path))
            return

        for next_val in range(2, n + 1):
            if used[next_val] or (path[-1] + next_val) not in squares:
                continue

            used[next_val] = 1
            path.append(next_val)

            dfs()

            used[next_val] = 0
            path.pop()

    dfs()
    return all_solutions

Thank you Team PWC, once again.

Happy Hacking!!

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     (4516)
 2. Rust       (1195)
 3. C          (1055)
 4. Ruby       (935)
 5. Haskell    (934)
 6. Lua        (919)
 7. C++        (737)
 8. Go         (722)
 9. JavaScript (648)
10. Java       (532)

Blogs with Creative Title

1. Hamiltonian Question Mark by Arne Sommer.

2. Hamiltonian Marks by Jorg Sommrey.

3. The Recursive Challenge by Matthias Muth.

4. The World Turned Upside Down! by Packy Anderson.

5. Hamilton’s questions by Peter Campbell Smith.

6. Questioning the Cycle by Roger Bell_West.

7. The Hamiltonian Question by Simon Green.

GitHub Repository Stats

1. Commits: 50,589 (+79)

2. Pull Requests: 14,426 (+25)

3. Contributors: 282 (+1)

4. Fork: 353

5. Stars: 218 (+1)

SPONSOR

With start of Week #355, we have a new sponsor Marc Perry until the end of year 2026. 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. You can find more informations here.

RECAP

Quick recap of The Weekly Challenge - 382 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

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 #382.

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

Task 1: Similar List

Submitted by: Mohammad Sajid Anwar

You are given three list of strings.

Write a script to find out if the first two list are similar with the help the third list. The third list contains the similar words map.

Example 1

Input: $list1 = ("great", "acting")
       $list2 = ("fine", "drama")
       $list3 = (["great", "fine"], ["acting", "drama"])
Output: true

Example 2

Input: $list1 = ("apple", "pie")
       $list2 = ("banana", "pie")
       $list3 = (["apple", "peach"], ["peach", "banana"])
Output: false

Example 3

Input: $list1 = ("perl4", "python")
       $list2 = ("raku", "python")
       $list3 = (["perl4", "perl5", "raku"])
Output: true

Example 4

Input: $list1 = ("enjoy", "challenge")
       $list2 = ("love", "weekly", "challenge")
       $list3 = (["enjoy", "love"])
Output: false

Example 5

Input: $list1 = ("fast", "car")
       $list2 = ("quick", "vehicle")
       $list3 = (["quick", "fast"], ["vehicle", "car"])
Output: true

Task 2: Nearest RGB

Submitted by: Mohammad Sajid Anwar

You are given a 6-digit hex color.

Write a script to round the RGB channels to the nearest web-safe value and return the nearest RGB color.

00 (0), 33 (51), 66 (102), 99 (153), CC (204) and FF (255)

Example 1

Input: $color = "#F4B2D1"
Output: "#FF99CC"

Red: F4 (Decimal 244), closer to 255 => FF
Green: B2 (Decimal 178), closer to 153 => 99
Blue: D1 (Decimal 209), closer to 204 => CC
So the nearest RGB: "#FF99CC"

Example 2

Input: $color = "#15E6E5"
Output: "#00FFCC"

Red: 15 (Decimal 21), closer to 0 => 00
Green: E6 (Decimal 230), closer to 255 => FF
Blue: E5 (Decimal 229), closer to 204 => CC

Example 3

Input: $color = "#191A65"
Output: "#003366"

Red: 19 (Decimal 25), closer to 0 => 00
Green: 1A (Decimal 26), closer to 51 => 33
Blue: 65 (Decimal 101), closer to 102 => 66

Example 4

Input: $color = "#2D5A1B"
Output: "#336633"

Red: 2D (Decimal 45), closer to 51 => 33
Green: 5A (Decimal 90), closer to 102 => 66
Blue: 1B (Decimal 27), closer to 51 => 33

Example 5

Input: $color = "#00FF66"
Output: "#00FF66"

Red: 00 (Decimal 0), closer to 0 => 00
Green: FF (Decimal 255), closer to 255 => FF
Blue: 66 (Decimal 102), closer to 102 => 66

By submitting a response to the challenge you agree that your name or pseudonym, any photograph you supply and any other personal information contained in your submission may be published on this website and the associated mobile app. Last date to submit the solution 23:59 (UK Time) Sunday 26th July 2026.