#!/usr/bin/perl

# Peter Campbell Smith - 2022-09-28
# PWC 184 task 1

use v5.28;
use utf8;
use warnings;

# You are given list of strings in the format aa9999 i.e. first 2 characters can be anything 'a-z' 
# followed by 4 digits '0-9'. Write a script to replace the first two characters with sequence starting 
# with '00', '01', '02' etc.

# Blog: 

my (@lists, $list_ref, @list, $old_show, $new_show, $j);

# inputs
@lists = (['ab1234', 'cd5678', 'ef1342'], ['pq1122', 'rs3334']);

# loop over inputs
while ($list_ref = shift @lists) {
	@list = @$list_ref;
	$old_show = $new_show = '';

	# loop over list elements
	for $j (0 .. scalar @list - 1) {
		$old_show .= qq['$list[$j]', ];
		$new_show .= qq['] . sprintf('%02d%s', $j, substr($list[$j], 2)) . qq[', ];
	}
	
	# show the answer
	say qq[\nInput:  (] . substr($old_show, 0, -2) . qq[)] .
		qq[\nOutput: (] . substr($new_show, 0, -2) . qq[)];
}