38 lines
1,011 B
Haskell
38 lines
1,011 B
Haskell
import Data.Bifunctor
|
|
import Data.List
|
|
import Data.List.Split
|
|
import Lib
|
|
|
|
type Rule = (Int, Int)
|
|
|
|
type Input = ([Rule], [[Int]])
|
|
|
|
main :: IO ()
|
|
main = aoc 2024 5 setup solve1 solve2 ["1"]
|
|
|
|
solve1 :: Input -> Int
|
|
solve1 = uncurry ((.) (sum . map mid) . (filter . (((==) <*>) . sortUpdate)))
|
|
|
|
solve2 :: Input -> Int
|
|
solve2 = uncurry (((.) . ((.) sum . (map . ((.) mid . sortUpdate)))) <*> (filter . (((/=) <*>) . sortUpdate)))
|
|
|
|
setup :: String -> Input
|
|
setup = fork (,) (parseRules . takeWhile (not . null)) (parseUpdates . dropWhile (not . null)) . lines
|
|
|
|
parseRules :: [String] -> [Rule]
|
|
parseRules = map (listToTuple . map read . splitOn "|")
|
|
|
|
parseUpdates :: [String] -> [[Int]]
|
|
parseUpdates = map (map read . splitOn ",") . filter (not . null)
|
|
|
|
sortUpdate :: [Rule] -> [Int] -> [Int]
|
|
sortUpdate = sortBy . cmpPages
|
|
|
|
cmpPages :: [Rule] -> Int -> Int -> Ordering
|
|
cmpPages rules a b
|
|
| (a, b) `elem` rules = LT
|
|
| (b, a) `elem` rules = GT
|
|
| otherwise = EQ
|
|
|
|
mid :: [a] -> a
|
|
mid = (!!) <*> (`div` 2) . length
|