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Diffstat (limited to '2024/17-Chronospatial_Computer/first.hs')
-rw-r--r-- | 2024/17-Chronospatial_Computer/first.hs | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/2024/17-Chronospatial_Computer/first.hs b/2024/17-Chronospatial_Computer/first.hs new file mode 100644 index 0000000..8c28db5 --- /dev/null +++ b/2024/17-Chronospatial_Computer/first.hs @@ -0,0 +1,66 @@ +-- requires cabal install --lib megaparsec parser-combinators heap vector +module Main (main) where + +import Control.Monad (void, when) +import Data.Bits +import Data.Functor +import qualified Data.List as L +import Data.Void (Void) +import Text.Megaparsec +import Text.Megaparsec.Char + +exampleExpectedOutput = "4,6,3,5,6,3,5,2,1,0" + +type Register = Int +type Op = Int +data Input = Input [Register] [Op] deriving Show + +type Parser = Parsec Void String + +parseNumber :: Parser Int +parseNumber = read <$> some digitChar + +parseRegister :: Parser Register +parseRegister = string "Register " *> (char 'A' <|> char 'B' <|> char 'C') *> string ": " *> parseNumber + +parseInput' :: Parser Input +parseInput' = Input <$> some (parseRegister <* eol) <* eol + <*> (string "Program: " *> some (parseNumber <* optional (char ',')) <* eol <* eof) + +parseInput :: String -> IO Input +parseInput filename = do + input <- readFile filename + case runParser parseInput' filename input of + Left bundle -> error $ errorBundlePretty bundle + Right input' -> return input' + +type Pointer = Int +type PState = (Pointer, [Register], [Int]) + +compute :: Input -> String +compute (Input start ops) = L.intercalate "," . L.reverse . map show . (\(_, _, s) -> s) $ step (0, start, []) + where + end = length ops + step :: PState -> PState + step ps@(p, [a, b, c], _) | p == end = ps + | otherwise = step $ i ps co + where + i = [adv, bxl, bst, jnz, bxc, out, bdv, cdv] L.!! (ops L.!! p) + co = [0, 1, 2, 3, a, b, c] L.!! (ops L.!! (p+1)) + adv (p, [a, b, c], acc) n = (p+2, [a `div` (2 ^ n), b, c], acc) + bxl (p, [a, b, c], acc) n = (p+2, [a, xor b n, c], acc) + bst (p, [a, b, c], acc) n = (p+2, [a, n `mod` 8, c], acc) + jnz (p, [0, b, c], acc) n = (p+2, [0, b, c], acc) + jnz (p, [a, b, c], acc) n = (n, [a, b, c], acc) + bxc (p, [a, b, c], acc) _ = (p+2, [a, xor b c, c], acc) + out (p, [a, b, c], acc) n = (p+2, [a, b, c], (n `mod` 8) : acc) + bdv (p, [a, b, c], acc) n = (p+2, [a, a `div` (2 ^ n), c], acc) + cdv (p, [a, b, c], acc) n = (p+2, [a, b, a `div` (2 ^ n)], acc) + +main :: IO () +main = do + example <- parseInput "example" + let exampleOutput = compute example + when (exampleOutput /= exampleExpectedOutput) (error $ "example failed: got " ++ show exampleOutput ++ " instead of " ++ show exampleExpectedOutput) + input <- parseInput "input" + print $ compute input |