25 lines
795 B
Haskell
25 lines
795 B
Haskell
import Data.List.Split
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import Data.List
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import Data.Maybe
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main = do
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content <- (map (splitOn ")") . lines) <$> readFile "input"
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print $ day6a content
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print $ day6b content
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day6a l = sum $ map (day6a' (transpose l) l) l
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day6a' l l2 (s:t)
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| s `elem` (l!!1) = 1 + day6a' l l2 next_pair
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| otherwise = 1
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where next_pair = l2 !! (fromJust $ elemIndex s (l!!1))
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day6b :: [[String]] -> Int
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day6b l = day6b' l "YOU" "SAN" [] - 2
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day6b' l s t visited
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| [s,t]`elem`l||[t,s]`elem`l=1
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| otherwise = 1 + minimum next_nodes
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where neighbours a = filter (/=a) $ concat
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[if x==a then xs else [] | xs<-l, x<-xs]
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next_nodes = [if x `elem` visited then maxBound -1
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else day6b' l x t (x:visited)| x<-neighbours s]
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