26 行
880 B
Haskell
26 行
880 B
Haskell
module Day5.Part1 (
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executeOperation,
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day5_1
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) where
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import qualified Data.Sequence as S
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import Data.Foldable (toList)
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import Day5.Shared
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executeOperation :: Row -> Operation -> Row
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executeOperation row op
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| count op == 1 = updatedRow
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| otherwise = executeOperation updatedRow (Operation { count = count op - 1, from = from op, to = to op })
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where
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originStack = row `S.index` asInt (from op)
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targetStack = row `S.index` asInt (to op)
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movedContent = head $ content originStack
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updatedOrigin = Stack (drop 1 $ content originStack)
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updatedTarget = Stack (movedContent : content targetStack)
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updatedRow = S.update (asInt $ to op) updatedTarget $ S.update (asInt $ from op) updatedOrigin row
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day5_1 :: String -> String
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day5_1 input = toList . findTopOfStacks $ foldl executeOperation row operations
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where
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(row, operations) = parseInput input
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