36 lines
1.5 KiB
Haskell
36 lines
1.5 KiB
Haskell
module Part2 where
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import Commons
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getNumberNeighbors :: Coordinates -> [NumberPart] -> Int
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getNumberNeighbors _ [] = 0
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getNumberNeighbors symbolCoordinates (h: t)
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| symbolCoordinates `elem` neighbors h = 1 + getNumberNeighbors symbolCoordinates t
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| otherwise = getNumberNeighbors symbolCoordinates t
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isGear :: SymbolPart -> [NumberPart] -> Bool
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isGear symbolPart numberParts | symbol symbolPart == '*' = getNumberNeighbors (coordinates symbolPart) numberParts == 2
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| otherwise = False
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getRatioNeighbors :: Coordinates -> [NumberPart] -> Int
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getRatioNeighbors _ [] = 1
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getRatioNeighbors symbolCoordinates (h: t)
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| symbolCoordinates `elem` neighbors h = value h * getRatioNeighbors symbolCoordinates t
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| otherwise = getRatioNeighbors symbolCoordinates t
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getGearRatio :: SymbolPart -> [NumberPart] -> Int
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getGearRatio symbolPart numberParts
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| isGear symbolPart numberParts = getRatioNeighbors (coordinates symbolPart) numberParts
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| otherwise = 0
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getGearRatios :: [SymbolPart] -> [NumberPart] -> [Int]
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getGearRatios [] _ = []
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getGearRatios (h: t) numberParts = let gearRatio = getGearRatio h numberParts
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in if gearRatio > 0
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then gearRatio: getGearRatios t numberParts
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else getGearRatios t numberParts
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getGearRatiosFromEngine :: Engine -> [Int]
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getGearRatiosFromEngine engine = getGearRatios (symbols engine) $ numbers engine
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