Robbie's Perl Programming Blog

For those not familiar with "The Weekly Challenge", it is a weekly programming puzzle with two parts, with a new pair of tasks each Monday. You can find it here: The Weekly Challenge The Weekly Challenge for the week of 2026-02-02 through 2026-02-08 is #359. The tasks for challenge #359 are as follows: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Task 359-1: Digital Root Submitted by: Mohammad Sajid Anwar You are given a positive integer, $int. Write a function that calculates the additive persistence of a positive integer and also return the digital root. Digital root is the recursive sum of all digits in a number until a single digit is obtained. Additive persistence is the number of times you need to sum the digits to reach a single digit. Example #1: Input: $int = 38 Expected output: Digital Root = 2; Persistence = 2 Example #2: Input: $int = 7 Expected output: Digital Root = 7; Persistence = 0 Example #3: Input: $int = 999 Expected output: Di...

For those not familiar with "The Weekly Challenge", it is a weekly programming puzzle with two parts, with a new pair of tasks each Monday. You can find it here: The Weekly Challenge The Weekly Challenge for the week of 2026-01-26 through 2026-02-01 is #358. The tasks for challenge #358 are as follows: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Task 358-1: Max Str Value Submitted by: Mohammad Sajid Anwar You are given an array of alphanumeric string, @strings. Write a script to find the max "value" of alphanumeric string in the given array which is the numeric representation of the string if it consists of digits only, otherwise the length of the string. Example #1: Input: @strings = ("123", "45", "6") Output: 123 "123" -> 123 "45" -> 45 "6" -> 6 Example #2: Input: @strings = ("abc", "de", "fghi") Output: 4 "abc" -> 3 ...

For those not familiar with "The Weekly Challenge", it is a weekly programming puzzle with two parts, with a new pair of tasks each Monday. You can find it here: The Weekly Challenge The Weekly Challenge for the week of 2026-01-19 through 2026-01-25 is #357. The tasks for challenge #357 are as follows: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Task 357-1: Kaprekar Constant Submitted by: Mohammad Sajid Anwar Write a function that takes a 4-digit integer and returns how many iterations of the following algorithm are required to reach Kaprekar’s constant (6174). (For more information about Kaprekar's Constant, see "https://en.wikipedia.org/wiki/6174".) 1. Select any four-digit number that has at least two different digits (leading zeros are allowed). 2. Create two new four-digit numbers by arranging the original digits in a.) ascending and b.) descending order (adding leading zeros if necessary). 3. Subtract...

For those not familiar with "The Weekly Challenge", it is a weekly programming puzzle with two parts, with a new pair of tasks each Monday. You can find it here: The Weekly Challenge The Weekly Challenge for the week of 2026-01-12 through 2026-01-18 is #356. The tasks for challenge #356 are as follows: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Task 356-1: Kolakoski Sequence Submitted by: Mohammad Sajid Anwar You are given an integer, $int > 3. Write a script to generate the Kolakoski Sequence of given length $int and return the count of 1 in the generated sequence. Please follow the wikipedia page for more informations. Example #1: Input: $int = 4 Output: 2 (1)(22)(11)(2) => 1221 Example #2: Input: $int = 5 Output: 3 (1)(22)(11)(2)(1) => 12211 Example #3: Input: $int = 6 Output: 3 (1)(22)(11)(2)(1)(22) => 122112 Example #4: Input: $int = 7 Output: 4 (1)(22)(11)(2)(1)(22)(1) => 1221121 Example #5: Input: $int = 8 Output: 4 (1)(2...

For those not familiar with "The Weekly Challenge", it is a weekly programming puzzle with two parts, with a new pair of tasks each Monday. You can find it here: The Weekly Challenge The Weekly Challenge for the week of 2026-01-05 through 2026-01-11 is #355. The tasks for challenge #355 are as follows: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Task 355-1: Thousand Separator Submitted by: Mohammad Sajid Anwar You are given a positive integer, $int. Write a script to add thousand separator, "," and return as string. Example #1: Input: $int = 123 Output: "123" Example #2: Input: $int = 1234 Output: "1,234" Example #3: Input: $int = 1000000 Output: "1,000,000" Example #4: Input: $int = 1 Output: "1" Example #5: Input: $int = 12345 Output: "12,345" I'll write a subroutine which splits each integer to its decimal digits, then pops each digit from the right end of the array and append...

For those not familiar with "The Weekly Challenge", it is a weekly programming puzzle with two parts, with a new pair of tasks each Monday. You can find it here: The Weekly Challenge The Weekly Challenge for the week of 2025-12-29 through 2026-01-04 is #354. The tasks for challenge #354 are as follows: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Task 354-1: 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 inputs and corresponding expected outputs: ( # Example #1 input: [4, 2, 1, 3], # Expected output: [1, 2], [2, 3], [3, 4] # Example #2 input: [10, 100, 20, 30], # Expected output: [10, 20], [20, 30] # Example #3 input: [-5, -2, 0, 3], # Expected output: [-2, 0] # E...