79 lines
2.5 KiB
Haskell
79 lines
2.5 KiB
Haskell
|
-- requires cabal install --lib megaparsec parser-combinators
|
||
|
|
module Main (main) where
|
||
|
|
import Control.Monad (void, when)
|
||
|
|
import Data.Char qualified as C
|
||
|
|
import Data.Functor
|
||
|
|
import Data.List qualified as L
|
||
|
|
import Data.Map qualified as M
|
||
|
|
import Data.Maybe
|
||
|
|
import Data.Set qualified as S
|
||
|
|
import Data.Void (Void)
|
||
|
|
import Text.Megaparsec
|
||
|
|
import Text.Megaparsec.Char
|
||
|
|
|
||
|
|
exampleExpectedOutput = 281
|
||
|
|
|
||
|
|
type Input = [(Int, Int)]
|
||
|
|
|
||
|
|
type Parser = Parsec Void String
|
||
|
|
|
||
|
|
parseDigit :: Parser Int
|
||
|
|
parseDigit = (C.digitToInt <$> digitChar)
|
||
|
|
<|> (string "one" $> 1)
|
||
|
|
<|> (string "two" $> 2)
|
||
|
|
<|> (string "three" $> 3)
|
||
|
|
<|> (string "four" $> 4)
|
||
|
|
<|> (string "five" $> 5)
|
||
|
|
<|> (string "six" $> 6)
|
||
|
|
<|> (string "seven" $> 7)
|
||
|
|
<|> (string "eight" $> 8)
|
||
|
|
<|> (string "nine" $> 9)
|
||
|
|
<|> (letterChar *> parseDigit)
|
||
|
|
|
||
|
|
parseDigitReversed :: Parser Int
|
||
|
|
parseDigitReversed = (C.digitToInt <$> digitChar)
|
||
|
|
<|> (string "eno" $> 1)
|
||
|
|
<|> (string "owt" $> 2)
|
||
|
|
<|> (string "eerht" $> 3)
|
||
|
|
<|> (string "ruof" $> 4)
|
||
|
|
<|> (string "evif" $> 5)
|
||
|
|
<|> (string "xis" $> 6)
|
||
|
|
<|> (string "neves" $> 7)
|
||
|
|
<|> (string "thgie" $> 8)
|
||
|
|
<|> (string "enin" $> 9)
|
||
|
|
<|> (letterChar *> parseDigitReversed)
|
||
|
|
|
||
|
|
parseFirstAndLast :: String -> (Int, Int)
|
||
|
|
parseFirstAndLast str = (f, l)
|
||
|
|
where
|
||
|
|
f = case runParser parseDigit "parseDigit" str of
|
||
|
|
Left bundle -> error $ errorBundlePretty bundle
|
||
|
|
Right input' -> input'
|
||
|
|
l = case runParser parseDigitReversed "parseDigit" (reverse str) of
|
||
|
|
Left bundle -> error $ errorBundlePretty bundle
|
||
|
|
Right input' -> input'
|
||
|
|
|
||
|
|
parseInput' :: Parser Input
|
||
|
|
parseInput' = fmap parseFirstAndLast <$> some (some alphaNumChar <* 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'
|
||
|
|
|
||
|
|
process :: Int -> (Int, Int) -> Int
|
||
|
|
process acc l = acc + fst l * 10 + snd l
|
||
|
|
|
||
|
|
compute :: Input -> Int
|
||
|
|
compute = L.foldl' process 0
|
||
|
|
|
||
|
|
main :: IO ()
|
||
|
|
main = do
|
||
|
|
example <- parseInput "example2"
|
||
|
|
let exampleOutput = compute example
|
||
|
|
when (exampleOutput /= exampleExpectedOutput) (error $ "example failed: got " ++ show exampleOutput ++ " instead of " ++ show exampleExpectedOutput)
|
||
|
|
input <- parseInput "input"
|
||
|
|
print $ compute input
|