Sort letters

You are given two arrays, @letters and @weights. Write a script to sort the given array @letters based on the @weights.

Examples

Example 1
Input: @letters = ('R', 'E', 'P', 'L')
       @weights = (3, 2, 1, 4)
Output: PERL

Example 2
Input: @letters = ('A', 'U', 'R', 'K')
       @weights = (2, 4, 1, 3)
Output: RAKU

Example 3
Input: @letters = ('O', 'H', 'Y', 'N', 'P', 'T')
       @weights = (5, 4, 2, 6, 1, 3)
Output: PYTHON

Analysis

Inspection of the examples reveals that:

sorted[weights[j]] = letters[j]

And allowing for Perl's zero-based arrays that is exactly my solution.

I could have made it strictly one line by using @_ directly rather than copying the arguments of the subroutine into local arrays, but

$sorted[$_[1]->[$_] - 1] = $_[0]->[$_] 
   for 0 .. @{$_[0]} - 1;

is not very easy to read (but it does work).

Nice hack to get split string task with nice explanation. Well done.

This review may cover either or both challenges for this week.

Try it 

Try running the script with any input:

Your @letters =

example: e, h, o, l, l

Your @weights =

example: 2, 1, 5, 4, 3

⤡

#!/usr/bin/perl

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

use v5.26;    # The Weekly Challenge - 2024-07-22
use utf8;     # Week 279 - task 1 - Sort letters
use warnings; # Peter Campbell Smith
binmode STDOUT, ':utf8';

sort_letters(['R', 'E', 'P', 'L'], [3, 2, 1, 4]);
sort_letters(['A', 'U', 'R', 'K'], [2, 4, 1, 3]);
sort_letters(['a', 'C', 'e', 'e', 'g', 'h', 'l', 'l', 'n'], [3, 1, 6, 9, 8, 2, 4, 5, 7]);

sub sort_letters {
    
    my (@letters, @weights, @sorted);
    
    @letters = @{$_[0]};
    @weights = @{$_[1]};

    # rearrange the letters
    $sorted[$weights[$_] - 1] = $letters[$_] for 0 .. @letters - 1;

    printf(qq[\nInput:  \@letters = ('%s'), \@weights = (%s)\n], join(qq[', '], @letters), join(', ', @weights));
    printf(qq[Output: %s\n], join('', @sorted));
}

7 lines of code

Output from script

Input:  @letters = ('R', 'E', 'P', 'L'), @weights = (3, 2, 1, 4)
Output: PERL

Input:  @letters = ('A', 'U', 'R', 'K'), @weights = (2, 4, 1, 3)
Output: RAKU

Input:  @letters = ('a', 'C', 'e', 'e', 'g', 'h', 'l', 'l', 'n'),
   @weights = (3, 1, 6, 9, 8, 2, 4, 5, 7)
Output: Challenge