Stopping halfway, not fun anymore, moving on

This commit is contained in:
EEva (JPotier) 2020-12-29 10:45:52 +02:00
parent 2b0283a9b6
commit 0e07c95cc5

View file

@ -126,6 +126,72 @@ solvePart1 input = do
fullMem = foldMap (runInitBlock I.empty) . reverse fullMem = foldMap (runInitBlock I.empty) . reverse
-- --
-- Part 2 starts by redefining the meaning for the bits in the mask
--
data BM = BMUnchanged
| BMForceOne
| BMFloating
instance Show (BM)
where
show BMUnchanged = ""
show BMForceOne = "¹"
show BMFloating = "^"
type Mask2 = [BM]
data InitBlock2 = InitBlock2 { unMask2 :: Mask2, unInitLines2 :: [(Addr,Int)] }
deriving Show
data Program2 = Program2 { unMem2 :: Mem, unInits2 :: [InitBlock2] }
deriving Show
mkBM :: String -> Mask2
mkBM xs | length xs == 36 = map go xs
where
go '1' = BMForceOne
go '0' = BMUnchanged
go 'X' = BMFloating
go c = trace ("Illegal char: " <> show c) $ undefined
mkBM xs | otherwise = trace "Mask is not 36 bit long" $ undefined
-- We have to redo the parsing side, because we were too specific (gotcha!)
--
parseMask2 :: Parser Mask2
parseMask2 = do
maskStr <- "mask = " *> P.take 36
P.endOfLine
pure $ mkBM $ T.unpack maskStr
-- mem[x] = y
parseInitLines2 :: Parser (Addr,Int)
parseInitLines2 = do
x <- "mem[" *> P.decimal
y <- "] = " *> P.decimal
P.endOfLine
pure $ (x,y)
parseBlock2 :: Parser InitBlock2
parseBlock2 = do
mask <- parseMask2
ix <- P.many1 parseInitLines
pure $ InitBlock2 mask ix
parseInput2 :: Parser [InitBlock2]
parseInput2 = do
bx <- P.many1 parseBlock2
P.endOfInput
pure bx
applyMask2 :: Mask2 -> Int -> [BM]
applyMask2 xs a = map go (zip xs (showIntAtBase (2::Int) intToDigit a ""))
where
go (BMForceOne ,_ ) = BMForceOne
go (BMUnchanged,'1' ) = BMForceOne
go (BMUnchanged,'0' ) = BMUnchanged
go (BMFloating ,_ ) = BMFloating
go (nb,_) = trace "Invalid char in base 2 number" $ undefined
main :: IO () main :: IO ()
main = do main = do
@ -141,3 +207,7 @@ main = do
putStrLn ":: Day 14 - Part 1" putStrLn ":: Day 14 - Part 1"
print . solvePart1 . T.pack $ exampleData print . solvePart1 . T.pack $ exampleData
print . solvePart1 $ input print . solvePart1 $ input
putStrLn ":: Tests - Part 2"
print $ mkBM "000000000000000000000000000000X1001X"
print $ applyMask2 (mkBM "000000000000000000000000000000X1001X") (42::Int)
putStrLn ":: Day 14 - Part 2"