118 lines
4 KiB
Haskell
118 lines
4 KiB
Haskell
|
-- requires cabal install --lib megaparsec parser-combinators heap vector
|
||
|
|
module Main (main) where
|
||
|
|
|
||
|
|
import Control.Applicative.Permutations
|
||
|
|
import Control.Monad (void, when)
|
||
|
|
import qualified Data.Char as C
|
||
|
|
import Data.Either
|
||
|
|
import Data.Functor
|
||
|
|
import qualified Data.Heap as H
|
||
|
|
import qualified Data.List as L
|
||
|
|
import qualified Data.Map as M
|
||
|
|
import Data.Maybe
|
||
|
|
import qualified Data.Set as S
|
||
|
|
import qualified Data.Vector as V
|
||
|
|
import qualified Data.Vector.Unboxed as VU
|
||
|
|
import Data.Void (Void)
|
||
|
|
import Text.Megaparsec
|
||
|
|
import Text.Megaparsec.Char
|
||
|
|
|
||
|
|
import Debug.Trace
|
||
|
|
|
||
|
|
exampleExpectedOutput = 19114
|
||
|
|
|
||
|
|
data Category = X | M | A | S deriving (Eq, Show)
|
||
|
|
data Op = Gt | Lt deriving (Eq, Show)
|
||
|
|
data Action = Accept | Reject | Jmp String deriving (Eq, Show)
|
||
|
|
data Rule = Cmp Category Op Int Action | RuleAction Action deriving (Eq, Show)
|
||
|
|
type Workflow = (String, [Rule])
|
||
|
|
type Workflows = M.Map String [Rule]
|
||
|
|
data Part = Part Int Int Int Int deriving (Eq, Show)
|
||
|
|
type Parts = [Part]
|
||
|
|
data Input = Input Workflows Parts deriving (Eq, Show)
|
||
|
|
|
||
|
|
type Parser = Parsec Void String
|
||
|
|
|
||
|
|
parseCategory :: Parser Category
|
||
|
|
parseCategory = char 'x' $> X
|
||
|
|
<|> char 'm' $> M
|
||
|
|
<|> char 'a' $> A
|
||
|
|
<|> char 's' $> S
|
||
|
|
|
||
|
|
parseOp :: Parser Op
|
||
|
|
parseOp = char '>' $> Gt
|
||
|
|
<|> char '<' $> Lt
|
||
|
|
|
||
|
|
parseNumber :: Parser Int
|
||
|
|
parseNumber = read <$> some digitChar
|
||
|
|
|
||
|
|
parseLabel :: Parser String
|
||
|
|
parseLabel = try $ count' 2 4 letterChar
|
||
|
|
|
||
|
|
parseAction :: Parser Action
|
||
|
|
parseAction = char 'A' $> Accept
|
||
|
|
<|> char 'R' $> Reject
|
||
|
|
<|> (Jmp <$> parseLabel)
|
||
|
|
|
||
|
|
parseRule :: Parser Rule
|
||
|
|
parseRule = (RuleAction <$> parseAction)
|
||
|
|
<|> (Cmp <$> parseCategory <*> parseOp <*> parseNumber <* char ':' <*> parseAction)
|
||
|
|
|
||
|
|
parseWorkflow :: Parser Workflow
|
||
|
|
parseWorkflow = (,) <$> parseLabel <* char '{'
|
||
|
|
<*> some (parseRule <* optional (char ',')) <* char '}'
|
||
|
|
|
||
|
|
parseWorkflows :: Parser Workflows
|
||
|
|
parseWorkflows = M.fromList <$> some (parseWorkflow <* eol)
|
||
|
|
|
||
|
|
parsePart :: Parser Part
|
||
|
|
parsePart = Part <$> (string "{x=" *> parseNumber)
|
||
|
|
<*> (string ",m=" *> parseNumber)
|
||
|
|
<*> (string ",a=" *> parseNumber)
|
||
|
|
<*> (string ",s=" *> parseNumber <* char '}')
|
||
|
|
|
||
|
|
parseParts :: Parser Parts
|
||
|
|
parseParts = some (parsePart <* eol)
|
||
|
|
|
||
|
|
parseInput' :: Parser Input
|
||
|
|
parseInput' = Input <$> (parseWorkflows <* eol)
|
||
|
|
<*> (parseParts <* 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'
|
||
|
|
|
||
|
|
compute :: Input -> Int
|
||
|
|
compute (Input workflows parts) = sum $ map compute' parts
|
||
|
|
where
|
||
|
|
compute' :: Part -> Int
|
||
|
|
compute' (Part x m a s) = case evaluate entryPoint of
|
||
|
|
Accept -> x + m + a + s
|
||
|
|
Reject -> 0
|
||
|
|
where
|
||
|
|
evaluate :: [Rule] -> Action
|
||
|
|
evaluate (RuleAction (Jmp s):_) = evaluate $ workflows M.! s
|
||
|
|
evaluate (RuleAction a:_) = a
|
||
|
|
evaluate (Cmp cat op n r:xs) | matches cat op n x m a s = evaluate [RuleAction r]
|
||
|
|
| otherwise = evaluate xs
|
||
|
|
matches X Lt n x _ _ _ = x < n
|
||
|
|
matches X Gt n x _ _ _ = x > n
|
||
|
|
matches M Lt n _ m _ _ = m < n
|
||
|
|
matches M Gt n _ m _ _ = m > n
|
||
|
|
matches A Lt n _ _ a _ = a < n
|
||
|
|
matches A Gt n _ _ a _ = a > n
|
||
|
|
matches S Lt n _ _ _ s = s < n
|
||
|
|
matches S Gt n _ _ _ s = s > n
|
||
|
|
entryPoint = workflows M.! "in"
|
||
|
|
|
||
|
|
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
|