This is the puzzle of December 11, 2021 of the Advent Of Code solved with the Commodore 64 in Basic. This program earned earned me my 21st and 22nd star :-)
The puzzle is here: https://adventofcode.com/2021/day/11
The Basic source code is in the file "aoc.txt". The executable binary is in "aoc.prg".
Be patient, because the program runs about 1 hour and 20 minutes to solve both parts of the puzzle.
Here is a screen shot:
Have fun.
Norbert