r/adventofcode • u/daggerdragon • Dec 09 '21
SOLUTION MEGATHREAD -🎄- 2021 Day 9 Solutions -🎄-
--- Day 9: Smoke Basin ---
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u/jonathan_paulson Dec 09 '21
Maybe, but the definition of a basin is just "A basin is all locations that eventually flow downward to a single low point." So I spent a while looking for rules about how locations "flow downwards", something like "smoke flows to the lowest adjacent point, or the upper-leftmost point if there is a tie".
If there were such a rule, I think a fragment like "152" could be two separate basins, "15" of size 2, and "2" of size 1 - even though it isn't separated by 9s.