Reverse degree

You are given a string. Write a script to find the reverse degree of the given string.

For each character, multiply its position in the reversed alphabet
(‘a’ = 26, ‘b’ = 25, …, ‘z’ = 1) with its position in the string. Sum these products for all characters in the string to get the reverse degree.

Examples

Example 1
Input: $str = 'z'
Output: 1
Reverse alphabet value of 'z' is 1.
Position 1: 1 x 1
Sum of product: 1

Example 2
Input: $str = 'a'
Output: 26
Reverse alphabet value of 'a' is 26.
Position 1: 1 x 26
Sum of product: 26

Example 3
Input: $str = 'bbc'
Output: 147
Reverse alphabet value of 'b' is 25 and 'c' is 24.
Position 1: 1 x 25
Position 2: 2 x 25
Position 3: 3 x 24
Sum of product: 25 + 50 + 72 => 147

Example 4
Input: $str = 'racecar'
Output: 560
Reverse alphabet value of 'r' is 9, 'a' is 26, 'c' is 24 and 'e' is
   24.
Position 1: 1 x 9
Position 2: 2 x 26
Position 3: 3 x 24
Position 4: 4 x 22
Position 5: 5 x 24
Position 6: 6 x 26
Position 7: 7 x 9
Sum of product: 9 + 52 + 72 + 88 + 120 + 156 + 63

Example 5
Input: $str = 'zyx'
Output: 14
Reverse alphabet value of 'z' is 1, 'y' is 2 and 'x' is 3.
Position 1: 1 x 1
Position 2: 2 x 2
Position 3: 3 x 3
Sum of product: 1 + 4 + 9

Analysis

The Unicode code points given by ord('λ') for characters a-z are 97-122. What is required to calculate the reverse degree is thus 123 - ord('λ'), which will range from a = 26 to z = 1.

Add those together for each character in the string and that's its reverse degree.

Note that as in task 1 I have converted any upper case letters to lower case and removed any characters not in [a-z].

Try it 

#!/usr/bin/perl

# Blog: http://ccgi.campbellsmiths.force9.co.uk/challenge

use v5.26;    # The Weekly Challenge - 2026-06-29
use utf8;     # Week 380 - task 2 - Reverse degree
use warnings; # Peter Campbell Smith
binmode STDOUT, ':utf8';
use Encode;

reverse_degree('bbc');
reverse_degree('racecar');
reverse_degree('zyx');
reverse_degree('supercalifragilisticexpialidocious');

sub reverse_degree {
    
    my ($string, $j, $reverse_degree);
    
    # initialise
    $string = shift;
    say qq[\nInput:  '$string'];
    $string =~ s|[^a-z]||g;
    $string = lc($string);
    
    # calculate reverse degree
    for $j (0 .. length($string) - 1) {
        $reverse_degree +=
            ($j + 1) * (123 - ord(substr($string, $j, 1)));
    }

    say qq[Output: $reverse_degree];
}

10 lines of code

Output from script

Input:  'bbc'
Output: 147

Input:  'racecar'
Output: 560

Input:  'zyx'
Output: 14

Input:  'supercalifragilisticexpialidocious'
Output: 9387