14 lines
395 B
Haskell
14 lines
395 B
Haskell
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import Aoc
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import Data.List ( group, sort )
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step :: String -> String
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step = concat . concatMap (\cs -> [show $ length cs, [head cs]]) . group
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part1 :: String -> (Int, String)
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part1 x = (length after40, after40)
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where after40 = iterate step x !! 40
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part2 :: p -> String -> Int
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part2 _ after40 = length (iterate step after40 !! 10) -- only 10 more needed
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main = aocMain' single part1 part2
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