+++ /dev/null
-import Debug.Trace
-
--- import qualified Data.Text.IO as TIO
-
-import qualified Data.Map.Strict as M
-import Data.Map.Strict ((!))
-import qualified Data.PQueue.Prio.Min as P
-import qualified Data.Set as S
-import qualified Data.Sequence as Q
-import Data.Sequence ((<|), (|>), (><))
-import Data.Foldable (toList, foldr', foldl', all)
--- import Data.Maybe (fromJust)
--- import Data.List
-import Data.Char
-import Control.Monad.Reader
-import Control.Lens hiding ((<|), (|>))
--- import Data.Map.Lens
-
-
-type Position = (Integer, Integer) -- r, c
-
-type Keys = S.Set Char
-type PointOfInterest = M.Map Position Char
-
-data Explorer1 = Explorer1 { _explorer1Position :: Char
- , _explorer1KeysHeld :: Keys
- , _explorer1Travelled :: Int
- } deriving (Show)
-data Explorer4 = Explorer4 { _explorer4Position :: S.Set Char
- , _explorer4KeysHeld :: Keys
- , _explorer4Travelled :: Int
- } deriving (Show)
-makeFields ''Explorer1
-makeFields ''Explorer4
-
-type ExploredStates e = S.Set e
-
-type ExpandedCave = S.Set Position
-data ExpandedCaveComplex = ExpandedCaveComplex { _caveE :: ExpandedCave
- , _keysE :: PointOfInterest
- , _doors :: PointOfInterest
- } deriving (Eq, Ord, Show)
-makeLenses ''ExpandedCaveComplex
-
-data CaveEdge = CaveEdge { _keysRequired :: S.Set Char
- , _distance :: Int
- } deriving (Eq, Ord, Show)
-makeLenses ''CaveEdge
-
-type EdgeKey = (Char, Char)
-type Cave = M.Map EdgeKey CaveEdge
-
-data CaveComplex = CaveComplex { _cave :: Cave
- , _keys :: S.Set Char
- } deriving (Eq, Ord, Show)
-makeLenses ''CaveComplex
-
-type CaveContext = Reader CaveComplex
-
-data Agendum e = Agendum { _current :: e
- , _trail :: Q.Seq e
- , _cost :: Int} deriving (Show, Eq)
-type Agenda e = P.MinPQueue Int (Agendum e)
-
-
-instance Eq Explorer1 where
- e1 == e2 = (_explorer1Position e1 == _explorer1Position e2) && (_explorer1KeysHeld e1 == _explorer1KeysHeld e2)
-instance Eq Explorer4 where
- e1 == e2 = (_explorer4Position e1 == _explorer4Position e2) && (_explorer4KeysHeld e1 == _explorer4KeysHeld e2)
-
-instance Ord Explorer1 where
- e1 `compare` e2 =
- if _explorer1Position e1 == _explorer1Position e2
- then (_explorer1KeysHeld e1) `compare` (_explorer1KeysHeld e2)
- else (_explorer1Position e1) `compare`(_explorer1Position e2)
-instance Ord Explorer4 where
- e1 `compare` e2 =
- if _explorer4Position e1 == _explorer4Position e2
- then (_explorer4KeysHeld e1) `compare` (_explorer4KeysHeld e2)
- else (_explorer4Position e1) `compare`(_explorer4Position e2)
-
-
-class (Eq e, Ord e, Show e) => Explorer e where
- successors :: e -> CaveContext (Q.Seq e)
- estimateCost :: e -> CaveContext Int
- extendExplorer :: e -> EdgeKey -> CaveEdge -> e
- -- positionE :: e -> Position
- -- keysHeldE :: e -> Keys
- emptyExplorer :: e
-
-instance Explorer Explorer1 where
- successors explorer = -- return Q.empty
- do let here = explorer ^. position
- cavern <- asks _cave
- let kH = explorer ^. keysHeld
- let locations0 = M.filterWithKey (\k _ds -> edgeTouches here k) cavern
- let locations1 = M.filter (\e -> S.null ((e ^. keysRequired) `S.difference` kH)) locations0
- let succs = M.foldrWithKey' (\k e q -> (extendExplorer explorer k e) <| q) Q.empty locations1
- return succs
-
- estimateCost explorer = -- return 0
- do let here = explorer ^. position
- ks <- asks _keys
- cavern <- asks _cave
- let kH = explorer ^. keysHeld
- let unfound = ks `S.difference` kH
- let unfoundEdges = M.filterWithKey (\k _ -> (edgeTouches here k) && ((edgeOther here k) `S.member` unfound)) cavern
- let furthest = maximum $ (0:) $ map _distance $ M.elems unfoundEdges
- return $ max 0 $ furthest + (S.size unfound) - 1
- -- return $ S.size unfound
-
- emptyExplorer = Explorer1 { _explorer1Position = '0', _explorer1KeysHeld = S.empty, _explorer1Travelled = 0 }
-
- extendExplorer explorer edgeKey edge =
- explorer & position .~ there
- & keysHeld .~ kH'
- & travelled .~ d'
- where there = edgeOther (explorer ^. position) edgeKey
- kH' = S.insert there (explorer ^. keysHeld)
- d' = (explorer ^. travelled) + (edge ^. distance)
-
-instance Explorer Explorer4 where
- successors explorer = -- return Q.empty
- do let heres = explorer ^. position
- cavern <- asks _cave
- let kH = explorer ^. keysHeld
- let locations0 = M.filterWithKey (\k _ds -> anyEdgeTouch heres k) cavern
- let locations1 = M.filter (\e -> S.null ((e ^. keysRequired) `S.difference` kH)) locations0
- let succs = M.foldrWithKey' (\k e q -> (extendExplorer explorer k e) <| q) Q.empty locations1
- return succs
-
- estimateCost explorer = -- return 0
- do let heres = explorer ^. position
- ks <- asks _keys
- cavern <- asks _cave
- let kH = explorer ^. keysHeld
- let unfound = ks `S.difference` kH
- let unfoundEdges0 = M.filterWithKey (\k _ -> anyEdgeTouch heres k) cavern
- let unfoundEdges = M.filterWithKey (\k _ -> not $ anyEdgeTouch kH k) unfoundEdges0
- let furthest = maximum $ (0:) $ map _distance $ M.elems unfoundEdges
- return $ max 0 $ furthest + (S.size unfound) - 1
-
- emptyExplorer = Explorer4 { _explorer4Position = S.fromList "0123", _explorer4KeysHeld = S.empty, _explorer4Travelled = 0 }
-
- extendExplorer explorer edgeKey edge =
- explorer & position .~ pos'
- & keysHeld .~ kH'
- & travelled .~ d'
- where here = S.findMin $ S.filter (\p -> edgeTouches p edgeKey) (explorer ^. position)
- there = edgeOther here edgeKey
- kH' = S.insert there (explorer ^. keysHeld)
- d' = (explorer ^. travelled) + (edge ^. distance)
- pos' = S.insert there $ S.delete here (explorer ^. position)
-
-
-main :: IO ()
-main = do
- text <- readFile "data/advent18.txt"
- let (ccE, startPosition) = buildCaveComplex text
- -- print ccE
- print $ part1 ccE startPosition
- print $ part2 ccE startPosition
-
-
-part1 :: ExpandedCaveComplex -> Position -> Int
-part1 cavern startPosition = maybe 0 _cost result
- where cc = contractCave cavern [startPosition]
- explorer = emptyExplorer :: Explorer1
- result = runReader (searchCave explorer) cc
-
-part2 :: ExpandedCaveComplex -> Position -> Int
-part2 caveComplex0 (re, ce) = maybe 0 _cost result
- where
- startPositions = [(re - 1, ce - 1), (re - 1, ce + 1), (re + 1 , ce - 1), (re + 1, ce + 1)]
- cavern0 = _caveE caveComplex0
- cavern = cavern0 `S.difference` [(re, ce), (re + 1, ce), (re - 1, ce), (re, ce + 1), (re, ce - 1)]
- caveComplex = caveComplex0 {_caveE = cavern}
- cc = contractCave caveComplex startPositions
- explorer = emptyExplorer :: Explorer4
- result = runReader (searchCave explorer) cc
-
-
--- buildCaveComplex :: Explorer e => String -> (CaveComplex, e)
-buildCaveComplex :: String -> (ExpandedCaveComplex, Position)
-buildCaveComplex text = (ccE, startPosition)
- where (ccE, startPosition) = foldl' buildCaveRow (cc0, (0, 0)) $ zip [0..] rows
- cc0 = ExpandedCaveComplex {_caveE = S.empty, _keysE = M.empty, _doors = M.empty}
- -- explorer0 = emptyExplorer -- Explorer { _position = (0, 0), _keysHeld = S.empty }
- rows = lines text
-
-buildCaveRow :: (ExpandedCaveComplex, Position) -> (Integer, String) -> (ExpandedCaveComplex, Position)
-buildCaveRow (cc, explorers) (r, row) = foldl' (buildCaveCell r) (cc, explorers) $ zip [0..] row
-
-
-buildCaveCell :: Integer -> (ExpandedCaveComplex, Position) -> (Integer, Char) -> (ExpandedCaveComplex, Position)
-buildCaveCell r (cc, startPosition) (c, char)
- | char == '.' = (cc', startPosition)
- | char == '@' = (cc', here)
- | isLower char = (cc' { _keysE = M.insert here char $ _keysE cc'}, startPosition)
- | isUpper char = (cc' { _doors = M.insert here char $ _doors cc'}, startPosition)
- | otherwise = (cc, startPosition)
- where cc' = cc { _caveE = S.insert here $ _caveE cc }
- here = (r, c)
-
-
-
-mkEdgeKey a b = if a < b then (a, b) else (b, a)
-
-edgeTouches x (a, b)
- | x == a = True
- | x == b = True
- | otherwise = False
-
-anyEdgeTouch xs p = S.foldl' (\t x -> t || (edgeTouches x p)) False xs
-
-edgeOther x (a, b)
- | x == a = b
- | otherwise = a
-
-
-
-contractCave :: ExpandedCaveComplex -> [Position] -> CaveComplex
-contractCave expanded startPositions = cavern
- where explorers = M.fromList $ zip startPositions $ map intToDigit [0..]
- starts = M.union explorers $ _keysE expanded
- cavern0 = CaveComplex {_cave = M.empty, _keys = S.fromList $ M.elems $ _keysE expanded}
- cavern = M.foldrWithKey (contractFrom expanded) cavern0 starts
-
-contractFrom :: ExpandedCaveComplex -> Position -> Char -> CaveComplex -> CaveComplex
-contractFrom expanded startPos startKey cc = cc { _cave = M.union (_cave cc) reachables }
- where reachables = reachableFrom [(startPos, edge0)] S.empty expanded' startKey
- edge0 = CaveEdge {_keysRequired = S.empty, _distance = 0}
- expanded' = expanded {_keysE = M.delete startPos $ _keysE expanded}
-
-reachableFrom :: [(Position, CaveEdge)] -> (S.Set Position) -> ExpandedCaveComplex -> Char -> Cave
-reachableFrom [] _closed _expanded _startKey = M.empty
-reachableFrom ((here, edge):boundary) closed expanded startKey
- | here `S.member` closed = reachableFrom boundary closed expanded startKey
- | here `M.member` ks = M.insert edgeKey edge $ reachableFrom boundary closed' expanded startKey
- | here `M.member` drs = reachableFrom boundaryD closed' expanded startKey
- | otherwise = reachableFrom boundary' closed' expanded startKey
- where nbrs0 = S.intersection (_caveE expanded) $ possibleNeighbours here
- nbrs = S.difference nbrs0 closed
- closed' = S.insert here closed
- ks = _keysE expanded
- drs = _doors expanded
- edgeKey = mkEdgeKey startKey (ks!here)
- edge' = edge { _distance = (_distance edge) + 1}
- edgeD = edge' {_keysRequired = S.insert (toLower (drs!here)) (_keysRequired edge')}
- neighbours = S.map (\n -> (n, edge')) nbrs
- neighboursD = S.map (\n -> (n, edgeD)) nbrs
- boundary' = boundary ++ (S.toAscList neighbours)
- boundaryD = boundary ++ (S.toAscList neighboursD)
-
-possibleNeighbours :: Position -> S.Set Position
-possibleNeighbours (r, c) = [(r + 1, c), (r - 1, c), (r, c + 1), (r, c - 1)]
-
-
-searchCave :: (Explorer e, HasTravelled e Int, HasKeysHeld e Keys) => e -> CaveContext (Maybe (Agendum e))
-searchCave explorer =
- do agenda <- initAgenda explorer
- aStar agenda S.empty
-
-initAgenda :: (Explorer e, HasTravelled e Int, HasKeysHeld e Keys) => e -> CaveContext (Agenda e)
-initAgenda explorer =
- do cost <- estimateCost explorer
- return $ P.singleton cost Agendum { _current = explorer, _trail = Q.empty, _cost = cost}
-
-
-aStar :: (Explorer e, HasTravelled e Int, HasKeysHeld e Keys) => Agenda e -> ExploredStates e -> CaveContext (Maybe (Agendum e))
-aStar agenda closed
- -- | trace ("Peeping " ++ (show $ fst $ P.findMin agenda) ++ ": " ++ (show reached) ++ " <- " ++ (show $ toList $ Q.take 1 $ _trail $ currentAgendum) ++ " :: " ++ (show newAgenda)) False = undefined
- -- | trace ("Peeping " ++ (show $ _current $ snd $ P.findMin agenda) ) False = undefined
- | P.null agenda = return Nothing
- | otherwise =
- do let (_, currentAgendum) = P.findMin agenda
- let reached = _current currentAgendum
- nexts <- candidates currentAgendum closed
- let newAgenda = foldl' (\q a -> P.insert (_cost a) a q) (P.deleteMin agenda) nexts
- reachedGoal <- isGoal reached
- if reachedGoal
- then return (Just currentAgendum)
- else if reached `S.member` closed
- then aStar (P.deleteMin agenda) closed
- else aStar newAgenda (S.insert reached closed)
-
-
-isGoal :: (Explorer e, HasTravelled e Int, HasKeysHeld e Keys) => e -> CaveContext Bool
-isGoal explorer =
- do ks <- asks _keys
- return $ ks == (explorer ^. keysHeld)
-
-
-candidates :: (Explorer e, HasTravelled e Int, HasKeysHeld e Keys) => Agendum e -> ExploredStates e -> CaveContext (Q.Seq (Agendum e))
-candidates agendum closed =
- do let candidate = _current agendum
- let previous = _trail agendum
- succs <- successors candidate
- let nonloops = Q.filter (\s -> not $ s `S.member` closed) succs
- mapM (makeAgendum candidate previous) nonloops
-
-makeAgendum :: (Explorer e, HasTravelled e Int, HasKeysHeld e Keys) => e -> (Q.Seq e) -> e -> CaveContext (Agendum e)
-makeAgendum candidate previous new =
- do predicted <- estimateCost new
- return Agendum { _current = new
- , _trail = candidate <| previous
- , _cost = (new ^. travelled) + predicted
- }
\ No newline at end of file
projects / advent-of-code-19.git / blobdiff