17 lines
646 B
Haskell
17 lines
646 B
Haskell
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import Data.List.Split
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getInitialLine :: [Integer] -> [Integer]
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getInitialLine firstLine = tail $ scanl (+) 0 firstLine
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getNextLine :: [Integer] -> [Integer] -> [Integer]
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getNextLine prevLine currLine =
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tail $ scanl minSum (head prevLine) (zip prevLine currLine)
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where minSum currSum (up, left) = min (left + up) (left + currSum)
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main :: IO ()
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main = do
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contents <- readFile "p081_matrix.txt"
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let fileLines = lines contents
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let matrix = map (map read . (splitOn ",")) fileLines :: [[Integer]]
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let initialLine = getInitialLine $ head matrix
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print $ last $ foldl getNextLine initialLine $ tail matrix
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