68 lines
2.2 KiB
Haskell
68 lines
2.2 KiB
Haskell
|
import Control.Applicative
|
||
|
|
import Control.Monad
|
||
|
|
import Data.Char
|
||
|
|
import Data.Functor
|
||
|
|
import Data.List
|
||
|
|
import Data.List.Extra (stripSuffix)
|
||
|
|
import Data.List.Split
|
||
|
|
import Data.Maybe
|
||
|
|
import Text.Read
|
||
|
|
import Data.Set (Set, fromList, isSubsetOf)
|
||
|
|
|
||
|
|
data Attr = Byr | Iyr | Eyr | Hgt | Hcl | Ecl | Pid | Cid
|
||
|
|
deriving (Show, Bounded, Enum, Eq, Ord)
|
||
|
|
|
||
|
|
intval :: Int -> Int -> Int -> Maybe Int
|
||
|
|
intval lo hi n = guard (lo <= n && n <= hi) $> n
|
||
|
|
|
||
|
|
nDigits :: Int -> String -> Maybe String
|
||
|
|
nDigits n s = guard (length s == n && all isDigit s) $> s
|
||
|
|
|
||
|
|
hexColor :: String -> Maybe String
|
||
|
|
hexColor s = guard (length s == 7 && s !! 0 == '#' && all (flip elem "0123456789abcdef") (drop 1 s)) $> s
|
||
|
|
|
||
|
|
validEcl :: String -> Bool
|
||
|
|
validEcl = flip elem ["amb", "blu", "brn", "gry", "grn", "hzl", "oth"]
|
||
|
|
|
||
|
|
parseAttr :: String -> Maybe Attr
|
||
|
|
parseAttr s =
|
||
|
|
case splitOn ":" s of
|
||
|
|
[key, value] -> case key of
|
||
|
|
"byr" -> (readMaybe value >>= intval 1920 2002) $> Byr
|
||
|
|
"iyr" -> (readMaybe value >>= intval 2010 2020) $> Iyr
|
||
|
|
"eyr" -> (readMaybe value >>= intval 2020 2030) $> Eyr
|
||
|
|
"hgt" ->
|
||
|
|
let inch = stripSuffix "cm" value >>= readMaybe >>= intval 150 193 in
|
||
|
|
let cm = stripSuffix "in" value >>= readMaybe >>= intval 59 76 in
|
||
|
|
(inch <|> cm) $> Hgt
|
||
|
|
"hcl" -> hexColor value $> Hcl
|
||
|
|
"ecl" -> if validEcl value then Just Ecl else Nothing
|
||
|
|
"pid" -> nDigits 9 value $> Pid
|
||
|
|
"cid" -> Just Cid
|
||
|
|
_ -> Nothing
|
||
|
|
_ -> Nothing
|
||
|
|
|
||
|
|
processLine :: String -> Maybe [Attr]
|
||
|
|
processLine = mapM parseAttr . splitOn " "
|
||
|
|
|
||
|
|
requiredAttrs :: Set Attr
|
||
|
|
requiredAttrs = fromList $ enumFromTo Byr Pid
|
||
|
|
|
||
|
|
combineAttrs :: [Attr] -> Maybe [Attr]
|
||
|
|
combineAttrs attrs = guard (isSubsetOf requiredAttrs $ fromList $ attrs) $> attrs
|
||
|
|
|
||
|
|
processPassport :: [String] -> Maybe [Attr]
|
||
|
|
processPassport = combineAttrs . concat <=< mapM processLine
|
||
|
|
|
||
|
|
processLines :: [String] -> [Maybe [Attr]]
|
||
|
|
processLines = map processPassport . splitWhen (== "")
|
||
|
|
|
||
|
|
countValid :: [Maybe [Attr]] -> Int
|
||
|
|
countValid = length . filter isJust
|
||
|
|
|
||
|
|
main :: IO ()
|
||
|
|
main = do
|
||
|
|
content <- readFile "4.txt"
|
||
|
|
let valid = countValid $ processLines $ lines content
|
||
|
|
print valid
|