advent-of-code/2023/day04/Main2.hs
2024-12-01 05:55:27 +01:00

27 lines
835 B
Haskell

import Data.List.Split (splitOn)
getGame :: String -> String
getGame s = tail $ dropWhile (/= ':') s
splitGame :: String -> [[String]]
splitGame s = map (\x -> filter (/= "") (splitOn [' '] x)) (splitOn ['|'] s)
calcPoints :: [(Int, Int)] -> (Int, [(Int, Int)]) -> (Int, [(Int, Int)])
calcPoints dict (num_cards, []) = (num_cards, [])
calcPoints dict (num_cards, this) =
let new_wins = map (\(i, w) -> take w (drop i dict)) this
in calcPoints dict (num_cards + length new_wins, concat new_wins)
main :: IO ()
main = do
inputLines <- lines <$> getContents
let games = map (\x -> splitGame (getGame x)) inputLines
let wins = zip [1..] (map (\[w, cards] -> length (filter (\card -> elem card w) cards)) games) :: [(Int, Int)]
-- let points = map calcPoints wins
print (calcPoints wins (0, wins))
-- print (wins)