56 lines
1.4 KiB
Haskell
56 lines
1.4 KiB
Haskell
import Data.Bits ( complement, Bits (shift, shiftR, rotate, complementBit), shiftL, (.|.) )
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import Data.List (transpose, isPrefixOf, inits, find, tails, sort)
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import Debug.Trace
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import Data.Maybe
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main :: IO ()
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main = readFile "3/input.txt" >>= print . solve . parse . lines
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parse :: [String] -> [String]
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parse = id
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solve :: [String] -> (Int,Int)
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solve input = (f input, g input)
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where f = powerUse . transpose
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g = lifeSupport
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powerUse :: [String] -> Int
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powerUse i = gamma i * epsilon i
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where
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gamma = pack . rate (>=)
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epsilon = pack . rate (<)
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rate :: (Int -> Int -> Bool) -> [String] -> [Int]
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rate op = foldr (\c -> (:) (
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let ones = count '1' c;
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zeroes = count '0' c;
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in if ones `op` zeroes
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then 1
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else 0
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)) []
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where
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count x = length . filter (== x)
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lifeSupport :: [String] -> Int
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lifeSupport i = oxygen x * scrubber x
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where
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x = reverse i
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oxygen = rating 0 (>=)
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scrubber = rating 0 (<)
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rating :: Int -> (Int -> Int -> Bool) -> [String] -> Int
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rating _ _ [result] = convert result
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rating n op list = rating (n + 1) op (filter (\a -> (a !! n) == (f (transpose list) !! n)) list)
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where
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f = map (head . show) . rate op
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pack :: [Int] -> Int
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pack = foldl f 0
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where
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f acc i = acc `shiftL` 1 .|. i
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unpack :: String -> [Int]
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unpack = map (\x -> if x == '0' then 0 else 1)
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convert = pack . unpack
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