AoC/2019/day18/day18.hs
2019-12-18 15:03:31 +01:00

63 lines
1.7 KiB
Haskell

{-# LANGUAGE LambdaCase #-}
module Main where
import Data.List
import Data.List.Split
import Data.List.Utils
import qualified Data.Map.Strict as M
import Data.Maybe
import Helpers
import Linear.V2
type DungeonMap = M.Map (V2 Int) Char
main :: IO ()
main = do
map <- updateScreenBuffer M.empty (0, 0) <$> readFile "testinput1"
putStrLn $ drawMap map
let spos = findPos '@' map
let epos = findPos 'e' map
print $ getNeighbors map spos
print $ getNeighborsMap map (getNeighbors map spos)
print $ distanceFromTo map '@' 'd'
updateScreenBuffer :: DungeonMap -> (Int, Int) -> String -> DungeonMap
updateScreenBuffer buf _ [] = buf
updateScreenBuffer buf (x, y) (a:as) = updateScreenBuffer bufNew coord as
where
bufNew =
if a /= '\n'
then M.insert (V2 x y) a buf
else buf
coord =
if a /= '\n'
then (x + 1, y)
else (0, y + 1)
getNeighbors :: DungeonMap -> V2 Int -> DungeonMap
getNeighbors m coord =
M.fromList
[ (u + coord, M.findWithDefault '#' (u + coord) m)
| u <- unitVecs
, M.findWithDefault '#' (u + coord) m /= '#'
]
getNeighborsMap :: DungeonMap -> DungeonMap -> DungeonMap
getNeighborsMap m n = M.unions [getNeighbors m x | (x, _) <- M.toList n]
distanceFromTo :: DungeonMap -> Char -> Char -> Int
distanceFromTo dmap schar echar =
distanceFromTo' dmap (M.singleton spos schar) spos epos 1
where
spos = findPos schar dmap
epos = findPos echar dmap
distanceFromTo' mMap nMap start end n =
if M.member end newNMap
then n
else distanceFromTo' mMap newNMap start end (n + 1)
where
newNMap = M.union nMap (getNeighborsMap mMap nMap)
findPos :: Char -> DungeonMap -> V2 Int
findPos c = head . M.keys . M.filter (`elem` [c])