Day 16: The Floor Will Be Lava
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C
Just tracing the ray. When it splits, recurse one way and continue the other. Didn’t bother with a direction lookup table this time, just a few ifs. The ray ends when it goes out of bounds or a ray in that direction has been previously traced on a given cell (this is tracked with a separate table).
It would’ve been straightforward if I hadn’t gotten the ‘previously visited’ check wrong 😞. I was checking against the direction coming in of the tile but marking the direction going out.
Ray function:
static void ray(int x, int y, int dir) { int c; while (x>=0 && y>=0 && x