13 lines
468 B
Haskell
13 lines
468 B
Haskell
circularSum :: [Int] -> Int
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circularSum ns = snd $ foldr (\n (prev, sum) -> (n, n * fromEnum (n == prev) + sum)) (last ns, 0) ns
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halfwaySum :: [Int] -> Int
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halfwaySum ns =
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let ms = drop (length ns `div` 2) ns ++ take (length ns `div` 2) ns
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in foldr (\(n, m) sum -> n * fromEnum (n == m) + sum) 0 $ zip ns ms
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main :: IO ()
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main = do
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nums <- fmap (map (read . pure)) $ readFile "1.txt"
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print $ circularSum nums
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print $ halfwaySum nums |