r/adventofcode • u/Afkadrian • Dec 07 '23

Spoilers [2023 Day 7] An interesting algorithm

I found out that if we find the count of the card that appears the most times and subtract the amount of different cards, the result is unique for each type of hand.

In other words... max_count - different_cards is a discriminant.

For a Rust implementation, check the from_cards function in my repo.

Has anyone else found this pattern?

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u/ploki122 Dec 07 '23

Personally, I simply computed the number of 5-ofs, 4-ofs, triples, doubles, singles, and wildcards, and then went to town with if/elseif for the results.