3 import Data.Text (Text)
4 -- import qualified Data.Text as T
5 import qualified Data.Text.IO as TIO
7 import Data.Attoparsec.Text hiding (take)
8 -- import Data.Attoparsec.Combinator
9 import Control.Applicative
16 import qualified Data.Map.Strict as M
17 import Data.Map.Strict ((!))
20 type MaskMap = M.Map Int Int
21 data Instruction = Mask MaskMap | Assignment Int64 Int64
24 type Memory = M.Map Int64 Int64
25 data Machine = Machine { mMemory :: Memory
30 emtpyMachine = Machine M.empty (complement 0) 0
35 do text <- TIO.readFile "data/advent14.txt"
36 let program = successfulParse text
37 print $ take 6 program
41 part1 program = sum $ M.elems $ mMemory finalMachine
42 where finalMachine = executeInstructions program
44 executeInstructions instructions =
45 foldl' executeInstruction emtpyMachine instructions
47 executeInstruction machine (Mask mask) = makeMask machine mask
48 executeInstruction machine (Assignment loc value) = assignValue machine loc value
51 makeMask machine mask =
52 machine {mMask0 = maskZeroes mask, mMask1 = maskOnes mask}
54 maskValue machine value =
55 (value .|. (mMask1 machine)) .&. (mMask0 machine)
57 assignValue machine loc value =
58 machine {mMemory = M.insert loc value' mem}
59 where value' = maskValue machine value
63 maskOnes :: MaskMap -> Int64
64 maskOnes mask = foldl' setBit zeroBits ones
65 where ones = M.keys $ M.filter (== 1) mask
67 maskZeroes :: MaskMap -> Int64
68 maskZeroes mask = complement $ foldl' setBit zeroBits ones
69 where ones = M.keys $ M.filter (== 0) mask
72 -- Parse the input file
74 programP = (maskP <|> assignmentP) `sepBy` endOfLine
76 maskP = maskify <$> ("mask = " *> (many (digit <|> letter)))
77 assignmentP = Assignment <$> ("mem[" *> decimal) <* "] = " <*> decimal
79 maskify :: String -> Instruction
80 maskify chars = Mask (M.fromList locNums)
81 where locChars = zip [0..] $ reverse chars
82 locDigits = filter (isDigit . snd) locChars
83 locNums = map (\(i, n) -> (i, read @Int [n])) locDigits
86 -- successfulParse :: Text -> (Integer, [Maybe Integer])
87 successfulParse input =
88 case parseOnly programP input of
89 Left _err -> [] -- TIO.putStr $ T.pack $ parseErrorPretty err
90 Right program -> program