The Weekly Challenge

HEADLINES

Welcome to the Week #343 of The Weekly Challenge.

Thank you, Ryan Thompson, for back to back contributions.

I have managed to contribute too, this time added Raku to the list as well, in addition to Perl and Python. I had a very busy last week, still found time luckily.

Are you guys taking part in Hacktoberfest?

Well, if you are unaware then let me tell you, The Weekly Challenge, is participating this year too like last time. So that means, your pull request should technical count towards the minimum pull request submission criteria. There was a time when I used to take part full on, not anymore. I would love to see, how many of Team PWC members are actively taking part in Hacktoberfest.

Please don’t push yourself too hard. Take it easy and enjoy the process.

Perl

#!/usr/bin/env perl

use v5.38;
use Test::More;

my @examples = (
    ["a0b1c2",  "0a1b2c" ],
    ["abc12",   "a1b2c"  ],
    ["0a2b1c3", "0a1b2c3"],
    ["1a23",    ""       ],
    ["ab123",   "1a2b3"  ],
);

for (@examples) {
    is(balance_string($_->[0]), $_->[1]);
}

done_testing;

sub balance_string($s) {
    # Extract all digits and sort them
    my @d = sort grep /\d/, split //, $s;
    # Extract all letters and sort them
    my @l = sort grep /\D/, split //, $s;

    # Return empty string if impossible
    return "" if abs(@d - @l) > 1;

    # If more digits than letters:
    @d > @l ?
        #   Join all elements into a string
        join "",
        #   For each index: digit + letter (or empty if no letter)
        map $d[$_] . ($l[$_] || ""),
        #   Iterate through all digit indices
        0..$#d
    :
    # If more letters than digits:
    @l > @d ?
        #   Join all elements into a string
        join "",
        #   For each index: letter + digit (or empty if no digit)
        map $l[$_] . ($d[$_] || ""),
        #   Iterate through all letter indices
        0..$#l
    # Else (equal counts):
    :
    # If first digit < first letter lexicographically:
    $d[0] lt $l[0] ?
        #   Join all elements into a string
        join "",
        #   For each index: digit + letter
        map $d[$_] . $l[$_],
        #   Iterate through all indices (both arrays same size)
        0..$#d
    :   # Else:
        #   Join all elements into a string
        join "",
        #   For each index: letter + digit
        map $l[$_] . $d[$_],
        #   Iterate through all indices (both arrays same size)
        0..$#d
}

Raku

#!/usr/bin/env raku

my @examples = (
    ["a0b1c2",  "0a1b2c" ],
    ["abc12",   "a1b2c"  ],
    ["0a2b1c3", "0a1b2c3"],
    ["1a23",    ""       ],
    ["ab123",   "1a2b3"  ],
);

for @examples -> @example {
    my ($input, $expected) = @example;
    my $result = balance-string($input);
    say "Pass: {$result eq $expected}";
}

sub balance-string(Str $s) {
    # Extract all digits and sort them
    my @d = $s.comb.grep({ /<digit>/ }).sort;
    # Extract all letters and sort them
    my @l = $s.comb.grep({ /<alpha>/ }).sort;

    # Return empty string if impossible
    return "" if abs(@d.elems - @l.elems) > 1;

    # If more digits than letters:
    if @d.elems > @l.elems {
        # Join all elements into a string
        return join "",
            # For each index: digit + letter (or empty if no letter)
            map { @d[$_] ~ (@l[$_] // "") },
            # Iterate through all digit indices
            0..^@d.elems;
    }
    # Else if more letters than digits:
    elsif @l.elems > @d.elems {
        # Join all elements into a string
        return join "",
            # For each index: letter + digit (or empty if no digit)
            map { @l[$_] ~ (@d[$_] // "") },
            # Iterate through all letter indices
            0..^@l.elems;
    }
    # Else (equal counts):
    else {
        # If first digit < first letter lexicographically:
        if @d[0] lt @l[0] {
            # Join all elements into a string
            return join "",
                # For each index: digit + letter
                map { @d[$_] ~ @l[$_] },
                # Iterate through all indices (both arrays same size)
                0..^@d.elems;
        }
        # Else:
        else {
            # Join all elements into a string
            return join "",
                # For each index: letter + digit
                map { @l[$_] ~ @d[$_] },
                # Iterate through all indices (both arrays same size)
                0..^@d.elems;
        }
    }
}

Python

#!/usr/bin/env python3

import re

def balance_string(s):
    # Extract all digits and sort them
    d = sorted([c for c in s if c.isdigit()])
    # Extract all letters and sort them
    l = sorted([c for c in s if c.isalpha()])

    # Return empty string if impossible
    if abs(len(d) - len(l)) > 1:
        return ""

    # If more digits than letters:
    if len(d) > len(l):
        # Join all elements into a string
        result = ""
        # For each index: digit + letter (or empty if no letter)
        for i in range(len(d)):
            result += d[i] + (l[i] if i < len(l) else "")
        return result
    # Else if more letters than digits:
    elif len(l) > len(d):
        # Join all elements into a string
        result = ""
        # For each index: letter + digit (or empty if no digit)
        for i in range(len(l)):
            result += l[i] + (d[i] if i < len(d) else "")
        return result
    # Else (equal counts):
    else:
        # If first digit < first letter lexicographically:
        if d[0] < l[0]:
            # Join all elements into a string
            result = ""
            # For each index: digit + letter
            for i in range(len(d)):
                result += d[i] + l[i]
            return result
        # Else:
        else:
            # Join all elements into a string
            result = ""
            # For each index: letter + digit
            for i in range(len(d)):
                result += l[i] + d[i]
            return result

examples = [
    ["a0b1c2",  "0a1b2c" ],
    ["abc12",   "a1b2c"  ],
    ["0a2b1c3", "0a1b2c3"],
    ["1a23",    ""       ],
    ["ab123",   "1a2b3"  ],
]

for example in examples:
    input_str, expected = example
    result = balance_string(input_str)
    print(f"Pass: {result == expected}")

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`
`338`	45	23	14
`339`	45	23	14
`340`	49	25	12
`341`	55	25	24
`342`	49	20	13

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


`Week`	`Guests`	`Contributions`	`Languages`
`338`	13	58	19
`339`	13	64	21
`340`	13	55	17
`341`	15	67	19
`342`	14	46	14

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     (3655)
 2. Rust       (1016)
 3. Ruby       (836)
 4. Haskell    (821)
 5. Lua        (775)
 6. C++        (657)
 7. C          (596)
 8. JavaScript (592)
 9. Go         (557)
10. BQN        (474)

Blogs with Creative Title

1. Maximum Balance by Arne Sommer.

2. And a 1, and a 2 by Bob Lied.

3. Balanced Adagio for Strings by Packy Anderson.

4. Fun with characters by Peter Campbell Smith.

5. Balanced Max Scores the String by Roger Bell_West.

6. Balancing the Score by Simon Green.

GitHub Repository Stats

1. Commits: 45,698 (`+101`)

2. Pull Requests: 12,792 (`+38`)

3. Contributors: 264

4. Fork: 337

5. Stars: 198 (`+1`)

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 - 342 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 #342.

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

Task 1: Zero Friend

Submitted by: Mohammad Sajid Anwar

You are given a list of numbers.

Find the number that is closest to zero and return its distance to zero.

Example 1

Input: @nums = (4, 2, -1, 3, -2)
Output: 1

Values closest to 0: -1 and 2 (distance = 1 and 2)

Example 2

Input: @nums = (-5, 5, -3, 3, -1, 1)
Output: 1

Values closest to 0: -1 and 1 (distance = 1)

Example 3

Input: @ums = (7, -3, 0, 2, -8)
Output: 0

Values closest to 0: 0 (distance = 0)
Exact zero wins regardless of other close values.

Example 4

Input: @nums = (-2, -5, -1, -8)
Output: 1

Values closest to 0: -1 and -2 (distance = 1 and 2)

Example 5

Input: @nums = (-2, 2, -4, 4, -1, 1)
Output: 1

Values closest to 0: -1 and 1 (distance = 1)

Task 2: Champion Team

Submitted by: Mohammad Sajid Anwar

You have n teams in a tournament. A matrix grid tells you which team is stronger between any two teams:

If grid[i][j] == 1, then team i is stronger than team j
If grid[i][j] == 0, then team j is stronger than team i

Find the champion team - the one with most wins, or if there is no single such team, the strongest of the teams with most wins. (You may assume that there is a definite answer.)

Example 1

Input: @grid = (
                 [0, 1, 1],
                 [0, 0, 1],
                 [0, 0, 0],
               )
Output: Team 0

[0, 1, 1] => Team 0 beats Team 1 and Team 2
[0, 0, 1] => Team 1 beats Team 2
[0, 0, 0] => Team 2 loses to all

Example 2

Input: @grid = (
                 [0, 1, 0, 0],
                 [0, 0, 0, 0],
                 [1, 1, 0, 0],
                 [1, 1, 1, 0],
               )
Output: Team 3

[0, 1, 0, 0] => Team 0 beats only Team 1
[0, 0, 0, 0] => Team 1 loses to all
[1, 1, 0, 0] => Team 2 beats Team 0 and Team 1
[1, 1, 1, 0] => Team 3 beats everyone

Example 3

Input: @grid = (
                 [0, 1, 0, 1],
                 [0, 0, 1, 1],
                 [1, 0, 0, 0],
                 [0, 0, 1, 0],
               )
Output: Team 0

[0, 1, 0, 1] => Team 0 beats teams 1 and 3
[0, 0, 1, 1] => Team 1 beats teams 2 and 3
[1, 0, 0, 0] => Team 2 beats team 0
[0, 0, 1, 0] => Team 3 beats team 2

Of the teams with 2 wins, Team 0 beats team 1.

Example 4

Input: @grid = (
                 [0, 1, 1],
                 [0, 0, 0],
                 [0, 1, 0],
               )
Output: Team 0

[0, 1, 1] => Team 0 beats Team 1 and Team 2
[0, 0, 0] => Team 1 loses to Team 2
[0, 1, 0] => Team 2 beats Team 1 but loses to Team 0

Example 5

Input: @grid = (
                 [0, 0, 0, 0, 0],
                 [1, 0, 0, 0, 0],
                 [1, 1, 0, 1, 1],
                 [1, 1, 0, 0, 0],
                 [1, 1, 0, 1, 0],
               )
Output: Team 2

[0, 0, 0, 0, 0] => Team 0 loses to all
[1, 0, 0, 0, 0] => Team 1 beats only Team 0
[1, 1, 0, 1, 1] => Team 2 beats everyone except self
[1, 1, 0, 0, 0] => Team 3 loses to Team 2
[1, 1, 0, 1, 0] => Team 4 loses to Team 2

Last date to submit the solution 23:59 (UK Time) Sunday 19th October 2025.