X-Git-Url: https://git.njae.me.uk/?p=advent-of-code-22.git;a=blobdiff_plain;f=advent22%2FMain.hs;h=848be83e062923f8148bd79046cfc307411d884f;hp=17f66898e93c286d9438e42dd3656f3f718c5a36;hb=refs%2Fheads%2Fmain;hpb=88d1ab058232b5590f33871b569fed9b0b9bed7c diff --git a/advent22/Main.hs b/advent22/Main.hs index 17f6689..848be83 100644 --- a/advent22/Main.hs +++ b/advent22/Main.hs @@ -1,6 +1,7 @@ -- Writeup at https://work.njae.me.uk/2022/12/19/advent-of-code-2022-day-18/ -import Debug.Trace +-- import Debug.Trace + import AoC import Prelude hiding (Left, Right) @@ -10,7 +11,6 @@ import Linear hiding (E) import Control.Lens import Data.Ix import Data.Maybe -import Data.List import Data.Char import Control.Monad.Reader @@ -62,6 +62,7 @@ main = print $ part2 field instrs -- print $ probeAllCorners field +part1, part2 :: FieldMap -> [PathElement] -> Int part1 fieldMap instrs = passwordOf endPerson where field = mkFlatField fieldMap startPos = V2 0 $ fromJust $ minimumOf (folded . filteredBy (_r . only 0) . _c) $ M.keysSet fieldMap @@ -199,8 +200,6 @@ crossEdge person face = (Down, F) -> person & position . _r .~ 0 & position . _c .~ (interpol c 100 149) (Left, F) -> person & position . _r .~ 0 & position . _c .~ (interpol r 50 99) & facing .~ Down - otherwise -> error ("Crossing illegal boundary " ++ show (person, face)) - where r = person ^. position . _r c = person ^. position . _c d = person ^. facing @@ -250,17 +249,21 @@ mkField rows = M.fromList | cell == '#' = Wall where cell = (rows !! r) !! c +isCell :: Int -> Int -> [String] -> Bool isCell r c rows = isRow && isCol && ((rows !! r) !! c) `elem` (".#" :: String) where isRow = r < length rows isCol = c < (length $ rows !! r) -mkInstructions :: String -> [PathElement] +mkInstructions, mkWalk, mkTurn :: String -> [PathElement] mkInstructions [] = [] -mkInstructions text@(t:ts) +mkInstructions text@(t:_) | isDigit t = mkWalk text | otherwise = mkTurn text + mkWalk text = (Forward $ read digits) : (mkInstructions remainder) where (digits, remainder) = span (isDigit) text + +mkTurn [] = [] mkTurn (t:ts) | t == 'R' = Clockwise : (mkInstructions ts) | t == 'L' = Anticlockwise : (mkInstructions ts)