The Weekly Challenge

10. TASK #2: Unique Fraction Generator

HEADLINES

Welcome to the Week #357 of The Weekly Challenge.

We’re slowly getting back into the swing of things after the long holiday season, and today I want to take a moment to talk about blogging. There was a time when I used to write about my weekly contributions, and I know firsthand the effort it takes to craft a tech blog post. Hats off to every one of you who takes the time to write and share - doing it week after week, without fail, is truly incredible. Code alone doesn’t tell the full story; it comes alive when the creator shares the journey behind it.

I’ve noticed that some members have taken it upon themselves to share solutions to past challenges, and it fills me with immense joy to see this energy and commitment. One day, I hope to look back and start contributing for all the weeks I’ve missed so far.

We are fortunate to have a group of dedicated members who haven’t missed a single week since joining the game. Seeing that same enthusiasm week after week is inspiring. Sometimes I feel the years catching up with me, yet the next moment I’m reminded of the passion that keeps me going. Ideally, I want to continue doing exactly what I’m doing today for as long as I can.

Sending lots of love and respect to each and every one of you.

Below is my contributions to the Task #1 of Week #356.

Perl: source code

sub count_one {
    my ($n) = @_;

    my @k = (1,2,2);
    my $i = 2;
    push @k, ($k[-1] ^ 3) x $k[$i++] while @k < $n;
    my $s = join("",@k[0..$n-1]);
    return $s =~ tr/1//;
}

Raku: source code

sub count_one($n) {
    my @k = 1, 2, 2;
    my $i = 2;

    @k.push: |((@k[*-1] +^ 3) xx @k[$i++]) while @k < $n;
    my $s = join("", @k[0..$n-1]);

    return +($s ~~ tr/1//);
}

Python: source code

def count_one(n):
    k = [1, 2, 2]
    i = 2

    while len(k) < n:
        val = k[-1] ^ 3
        count = k[i]
        i += 1
        k.extend([val] * count)

    s = "".join(map(str, k[0:n]))
    return s.count("1")

Thank you Team PWC, once again.

Happy Hacking!!

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


`Week`	`Perl`	`Raku`	`Blog`
`352`	52	21	26
`353`	54	20	24
`354`	54	23	16
`355`	51	23	24
`356`	44	18	13

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


`Week`	`Guests`	`Contributions`	`Languages`
`352`	16	73	22
`353`	16	73	19
`354`	15	61	18
`355`	17	69	21
`356`	13	39	11

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     (4014)
 2. Rust       (1088)
 3. Ruby       (862)
 4. Haskell    (851)
 5. Lua        (826)
 6. C++        (684)
 7. Go         (620)
 8. JavaScript (614)
 9. C          (600)
10. BQN        (497)

Blogs with Creative Title

1. Kolakoski Wins by Arne Sommer.

2. Self-Generating Games by Jorg Sommrey.

3. Kolakoski called, he wants his sequence back(!) by Marc Perry.

4. Who’s Kolakoski? by Packy Anderson.

5. Sequence and consequence by Peter Campbell Smith.

6. Kolakoski Wins by Roger Bell_West.

7. Winning sequence by Simon Green.

GitHub Repository Stats

1. Commits: 47,391 (`+120`)

2. Pull Requests: 13,385 (`+43`)

3. Contributors: 272

4. Fork: 350 (`+1`)

5. Stars: 209 (`+2`)

We are looking for sponsor for monthly prize pot of US $50. 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 - 356 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 #356.

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

Task 1: Kaprekar Constant

Submitted by: Mohammad Sajid Anwar

Write a function that takes a 4-digit integer and returns how many iterations are required to reach Kaprekar’s constant (6174). For more information about Kaprekar's Constant please follow the wikipedia page.

Example 1

Input: $int = 3524
Output: 3

Iteration 1: 5432 - 2345 = 3087
Iteration 2: 8730 - 0378 = 8352
Iteration 3: 8532 - 2358 = 6174

Example 2

Input: $int = 6174
Output: 0

Example 3

Input: $int = 9998
Output: 5

Iteration 1: 9998 - 8999 = 0999
Iteration 2: 9990 - 0999 = 8991
Iteration 3: 9981 - 1899 = 8082
Iteration 4: 8820 - 0288 = 8532
Iteration 5: 8532 - 2358 = 6174

Example 4

Input: $int = 1001
Output: 4

Iteration 1: 1100 - 0011 = 1089
Iteration 2: 9810 - 0189 = 9621
Iteration 3: 9621 - 1269 = 8352
Iteration 4: 8532 - 2358 = 6174

Example 5

Input: $int = 9000
Output: 4

Iteration 1: 9000 - 0009 = 8991
Iteration 2: 9981 - 1899 = 8082
Iteration 3: 8820 - 0288 = 8532
Iteration 4: 8532 - 2358 = 6174

Example 6

Input: $int = 1111
Output: -1

The sequence does not converge on 6174, so return -1.

Task 2: Unique Fraction Generator

Submitted by: Yary

Given a positive integer N, generate all unique fractions you can create using integers from 1 to N and follow the rules below:

- Use numbers 1 through N only (no zero)
- Create fractions like numerator/denominator
- List them in ascending order (from smallest to largest)
- If two fractions have the same value (like 1/2 and 2/4),
  only show the one with the smallest numerator

Example 1

Input: $int = 3
Output: 1/3, 1/2, 2/3, 1/1, 3/2, 2/1, 3/1

Example 2

Input: $int = 4
Output: 1/4, 1/3, 1/2, 2/3, 3/4, 1/1, 4/3, 3/2, 2/1, 3/1, 4/1

Example 3

Input: $int = 1
Output: 1/1

Example 4

Input: $int = 6
Output: 1/6, 1/5, 1/4, 1/3, 2/5, 1/2, 3/5, 2/3, 3/4,
        4/5, 5/6, 1/1, 6/5, 5/4, 4/3, 3/2, 5/3, 2/1,
        5/2, 3/1, 4/1, 5/1, 6/1

Example 5

Input: $int = 5
Output: 1/5, 1/4, 1/3, 2/5, 1/2, 3/5, 2/3, 3/4, 4/5, 1/1,
        5/4, 4/3, 3/2, 5/3, 2/1, 5/2, 3/1, 4/1, 5/1

Last date to submit the solution 23:59 (UK Time) Sunday 25th January 2026.