#+title: Challenge 185
#+date: 2022-10-04
#+html_link_up: ../
#+export_file_name: index
#+options: toc:nil
#+setupfile: ~/.emacs.d/org-templates/level-2.org

* Task 1 - MAC Address

You are given MAC address in the form i.e. ~hhhh.hhhh.hhhh~.

Write a script to convert the address in the form ~hh:hh:hh:hh:hh:hh~.

#+begin_src
Example 1

Input:  1ac2.34f0.b1c2
Output: 1a:c2:34:f0:b1:c2

Example 2

Input:  abc1.20f1.345a
Output: ab:c1:20:f1:34:5a
#+end_src

** Raku

~comb~ combs out alphanumeric characters and we simply print them. ":" is
printed after every 2 characters but not at the end.

#+begin_src raku
unit sub MAIN(
    Str $mac-address, #= MAC address (hhhh.hhhh.hhhh)
);

# Converts in hh:hh:hh:hh:hh:hh form.
for $mac-address.comb(/\w/) {
    .print;
    given $++ {
        when 11 { succeed; }
        when $_ !%% 2 { print ":" }
    }
}
#+end_src

* Task 2 - Mask Code

You are given a list of codes in many random format.

Write a script to mask first four characters (a-z,0-9) and keep the rest
as it is.

#+begin_src
Example 1

Input: @list = ('ab-cde-123', '123.abc.420', '3abc-0010.xy')
Output: ('xx-xxe-123', 'xxx.xbc.420', 'xxxx-0010.xy')

Example 2

Input: @list = ('1234567.a', 'a-1234-bc', 'a.b.c.d.e.f')
Output: ('xxxx567.a', 'x-xxx4-bc', 'x.x.x.x.e.f')
#+end_src

** Raku

Takes an array of codes as input. Loops over characters of a code and
prints every character except first four matching the regex "\w".

#+begin_src raku
unit sub MAIN(*@codes);

for @codes -> $code {
    my Int $count;
    for $code.comb {
        given $_ {
            when /\w/ { print ($count++ < 4 ?? "x" !! $_) }
            default { .print }
        }
    }
    put "";
}
#+end_src