Robbie Hatley's Solutions, in Perl, for The Weekly Challenge #321 (“Distinct Average” and “Backspace Compare”)

For those not familiar with "The Weekly Challenge", it is a weekly programming puzzle with two parts, with a new pair of taks each Monday. You can find it here:

The Weekly Challenge

The Weekly Challenge for the week of 2025-05-12 through 2025-05-18 is #321

The tasks for challenge #321 are as follows:

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Task 321-1: Distinct Average
Submitted by: Mohammad Sajid Anwar
You are given an array of numbers with even length. Write a
script to return a count of distinct averages. The averages
are calculated by removing the minimum and the maximum, then
averaging the two.

Example #1:
Input: @nums = (1, 2, 4, 3, 5, 6)
Output: 1
Step 1: Min = 1, Max = 6, Avg = 3.5
Step 2: Min = 2, Max = 5, Avg = 3.5
Step 3: Min = 3, Max = 4, Avg = 3.5
The count of distinct averages is 1.

Example #2:
Input: @nums = (0, 2, 4, 8, 3, 5)
Output: 2
Step 1: Min = 0, Max = 8, Avg = 4
Step 2: Min = 2, Max = 5, Avg = 3.5
Step 3: Min = 3, Max = 4, Avg = 3.5
The count of distinct averages is 2.

Example #3:
Input: @nums = (7, 3, 1, 0, 5, 9)
Output: 2
Step 1: Min = 0, Max = 9, Avg = 4.5
Step 2: Min = 1, Max = 7, Avg = 4
Step 3: Min = 3, Max = 5, Avg = 4
The count of distinct averages is 2.

After checking that each input array is, indeed, an even-length array of real numbers, I'll compute each "Min-Max Average" by doing the following:

1. Put list in increasing numerical order.
2. Loop while @sorted is not empty:
   1. Snip-off min and max.
   2. Compute next MMA ((min+max)/2) and push it to list @MMAs.
3. Compute number of unique MMAs using "sort", "unique", and "scalar".

Robbie Hatley's Perl Solution to The Weekly Challenge 321-1

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Task 321-2: Backspace Compare
Submitted by: Mohammad Sajid Anwar
You are given two strings containing zero or more #. Write a
script to return true if the two given strings are same by
treating # as backspace.

Example #1:
Input: $str1 = "ab#c"
       $str2 = "ad#c"
Output: true
For first string,  we remove "b" as it is followed by "#".
For second string, we remove "d" as it is followed by "#".
In the end both strings became the same.

Example #2:
Input: $str1 = "ab##"
       $str2 = "a#b#"
Output: true

Example #3:
Input: $str1 = "a#b"
       $str2 = "c"
Output: false

I'll solve this by simply doing what each "#" backspace character means: "erase this character, and the one to its left (if this is not the first character)". Then compare the processed strings.

Robbie Hatley's Perl Solution to The Weekly Challenge 321-2

That's it for challenge 321; see you on challenge 322!