Re 19,  I gave up trying to understand why there were only 24 possible 
orientations,  when I thought there should be 48, not knowing what they meant 
by “facing”.   Instead,  I used M = round B’ %. A’ for “matching” sets of 
coordinates A & B.  Finding these matching sets is the main part of the 
problem.  (A’ is the result of a minor tweak to A.)

Part 2 is trivial once you’ve done part 1.

As for problem 20... thought it was simple until I realised the problem with 
infinite extent, which doesn’t affect the example,  but does come into play for 
the actual data!

Mike

Sent from my iPad

> On 30 Dec 2021, at 13:31, David Lambert <[email protected]> wrote:
> 
> Laughing aloud, I haven't yet pretended to read those baffling instructions.
> 
>> On 12/30/21 7:00 AM, [email protected] wrote:
>> Date: Wed, 29 Dec 2021 19:44:34 +0000
>> From: "'Michael Day' via Chat"<[email protected]>
>> To:[email protected]
>> Subject: Re: [Jchat] Advent of Code
>> Message-ID:<[email protected]>
>> Content-Type: text/plain; charset=UTF-8; format=flowed
>> 
>> I've been stuck for ages on day 19, part 1 .... just couldn't see what
>> was wrong...
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm

Reply via email to