36 lines
870 B
Haskell
36 lines
870 B
Haskell
module Day02 (parse, solveA, solveB) where
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import Data.List (sort, tails)
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splitOn :: (Eq a) => a -> [a] -> [[a]]
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splitOn _ [] = []
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splitOn delimiter xs =
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let (before, remainder) = break (== delimiter) xs
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in before : case remainder of
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[] -> []
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_ : rest -> splitOn delimiter rest
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pairs :: [a] -> [(a, a)]
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pairs xs = [(x, y) | (x : ys) <- tails xs, y <- ys]
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parse :: String -> [[Int]]
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parse = map (map read . splitOn 'x') . lines
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toArea :: [Int] -> Int
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toArea = calculate . map (uncurry (*)) . pairs
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where
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calculate :: [Int] -> Int
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calculate sides = (sum . map (2 *)) sides + minimum sides
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solveA :: [[Int]] -> Int
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solveA = sum . map toArea
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solveB :: [[Int]] -> Int
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solveB = sum . map calcWrap
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where
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calcWrap :: [Int] -> Int
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calcWrap dims =
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let wrap = (2 *) . sum . take 2 $ sort dims
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bow = product dims
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in wrap + bow
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