Loooong time overdue. First drafts of the code
kept track of every id separately in a defaultdict.
This was not sustainable since the code examples
had some recurring ids, and after managing to
support the test cases the code was eay off for
the real puzzle input.
In the end, the whole code was deleted and replaced
by a BFS solution that expands the current regions
until it finds no more areas.
Got the trick to count all perimiters in an else clause
from a leaderboard placed youtuber.
Anders Englöf Ytterström
19aee1363a