copy pasting the rules from last year’s thread:
Rules: no spoilers.
The other rules are made up aswe go along.
Share code by link to a forge, home page, pastebin (Eric Wastl has one here) or code section in a comment.
day 8 part 2
Eric added some 0
s in the grid which fucked up my existence code, sneaky devil
I almost got done in by floating point arithmetic, I think
8-2 commentary
Used the coordinates of every two same type frequences to create the ilnear equation (y = ax + b) and then fed it all the matrix coordinates to see which belonged to the line. To get the correct number of antinodes I had to check for |y - ax - b| < 0.0001, otherwise I got around 20 too few.