--- /dev/null
+-- Writeup at https://work.njae.me.uk/2022/12/17/advent-of-code-2022-day-16/
+
+-- import Debug.Trace
+
+import AoC
+import Data.Text (Text)
+import qualified Data.Text.IO as TIO
+import Data.Attoparsec.Text hiding (take, D)
+import Control.Applicative
+import qualified Data.PQueue.Prio.Max as P
+import qualified Data.Set as S
+import qualified Data.Sequence as Q
+import qualified Data.Map.Strict as M
+import Data.Map.Strict ((!))
+-- import Data.Sequence ((|>), Seq((:|>)), ViewR ((:>)))
+import Data.Sequence ( (|>), Seq((:|>)) )
+import Data.List
+import Data.List.Split (chunksOf)
+import Data.Ord
+import Control.Monad.Reader
+import Control.Lens hiding ((<|), (|>), (:>), (:<), indices)
+
+
+type RoomID = String
+
+data Tunnel = Tunnel { _tunnelTo :: RoomID, _tunnelLength :: Int}
+ deriving (Eq, Show, Ord)
+makeLenses ''Tunnel
+
+data Room = Room
+ { _flowRate :: Int
+ , _tunnels :: S.Set Tunnel
+ } deriving (Eq, Show, Ord)
+makeLenses ''Room
+
+type Cave = M.Map RoomID Room
+data TimedCave = TimedCave { getCave :: Cave, getTimeLimit :: Int }
+
+type CaveContext = Reader TimedCave
+
+data SingleSearchState = SingleSearchState
+ { _currentRoom :: RoomID
+ , _currentTime :: Int
+ , _sOpenValves :: S.Set RoomID
+ } deriving (Eq, Show, Ord)
+makeLenses ''SingleSearchState
+
+data DoubleSearchState = DoubleSearchState
+ { _personRoom :: RoomID
+ , _personTime :: Int
+ , _elephantRoom :: RoomID
+ , _elephantTime :: Int
+ , _dOpenValves :: S.Set RoomID
+ } deriving (Eq, Show, Ord)
+makeLenses ''DoubleSearchState
+
+data Agendum s =
+ Agendum { _current :: s
+ , _trail :: Q.Seq s
+ , _trailBenefit :: Int
+ , _benefit :: Int
+ } deriving (Show, Eq, Ord)
+makeLenses ''Agendum
+
+type Agenda s = P.MaxPQueue Int (Agendum s)
+
+-- state, total flowed so far
+type ExploredStates s = S.Set (s, Int)
+
+
+class (Eq s, Ord s, Show s) => SearchState s where
+ emptySearchState :: RoomID -> s
+ currentFlow :: s -> CaveContext Int
+ timeOf :: s -> Int
+ successors :: s -> CaveContext (Q.Seq s)
+ -- estimateBenefit :: s -> Int -> CaveContext Int
+ estimateBenefit :: s -> CaveContext Int
+
+instance SearchState SingleSearchState where
+ emptySearchState startID = SingleSearchState
+ { _currentRoom = startID
+ , _currentTime = 0
+ , _sOpenValves = S.empty
+ }
+
+ currentFlow state =
+ do cave <- asks getCave
+ let valves = state ^. sOpenValves
+ let presentRooms = cave `M.restrictKeys` valves
+ return $ sumOf (folded . flowRate) presentRooms
+
+ timeOf state = state ^. currentTime
+
+ successors state =
+ do isFF <- isFullFlow state
+ -- cave <- asks getCave
+ timeLimit <- asks getTimeLimit
+ let here = state ^. currentRoom
+ let opened = state ^. sOpenValves
+ let now = state ^. currentTime
+ succs <- agentSuccessor now opened now here
+ let succStates = Q.fromList succs
+ if isFF || (Q.null succStates)
+ then return $ Q.singleton (state & currentTime .~ timeLimit)
+ else return succStates
+
+ estimateBenefit here =
+ do cave <- asks getCave
+ timeLimit <- asks getTimeLimit
+ let timeRemaining = timeLimit - (timeOf here)
+ cf <- currentFlow here
+ let closedValves = (cave `M.withoutKeys` (here ^. sOpenValves)) ^.. folded . flowRate
+ let sortedClosedValves = sortOn Down closedValves
+ let otherValveFlows = sum $ zipWith (*) [timeRemaining, (timeRemaining - 2) .. 0] sortedClosedValves
+ return $ (cf * timeRemaining) + otherValveFlows
+
+
+instance SearchState DoubleSearchState where
+ emptySearchState startID = DoubleSearchState
+ { _personRoom = startID
+ , _personTime = 0
+ , _elephantRoom = startID
+ , _elephantTime = 0
+ , _dOpenValves = S.empty
+ }
+
+ currentFlow state =
+ do cave <- asks getCave
+ let valves = S.toList $ state ^. dOpenValves
+ return $ sum $ fmap (\v -> (cave ! v) ^. flowRate) valves
+ -- let presentRooms = cave `M.restrictKeys` valves
+ -- return $ sumOf (folded . flowRate) presentRooms
+
+ timeOf state = min (state ^. personTime) (state ^. elephantTime)
+
+ successors state =
+ do isFF <- isFullFlow state
+ -- cave <- asks getCave
+ timeLimit <- asks getTimeLimit
+ let opened = state ^. dOpenValves
+ let pNow = state ^. personTime
+ let eNow = state ^. elephantTime
+ let now = min pNow eNow
+ let pHere = state ^. personRoom
+ let eHere = state ^. elephantRoom
+ pNexts <- agentSuccessor now opened pNow pHere
+ eNexts <- agentSuccessor now opened eNow eHere
+ let nexts = [ state & personRoom .~ (p ^. currentRoom)
+ & personTime .~ (p ^. currentTime)
+ & elephantRoom .~ (e ^. currentRoom)
+ & elephantTime .~ (e ^. currentTime)
+ & dOpenValves %~ (S.union (p ^. sOpenValves) . S.union (e ^. sOpenValves))
+ | p <- pNexts
+ , e <- eNexts
+ ]
+ let dedups = if pNow == eNow && pHere == eHere
+ then filter (\s -> (s ^. personRoom) < (s ^. elephantRoom)) nexts
+ else nexts
+ -- let succStates = trace ("Succs: in " ++ (show state) ++ " out " ++ (show dedups)) (Q.fromList dedups)
+ let succStates = Q.fromList dedups
+ if isFF || (Q.null succStates)
+ then return $ Q.singleton (state & personTime .~ timeLimit & elephantTime .~ timeLimit)
+ else return succStates
+
+ estimateBenefit here =
+ do cave <- asks getCave
+ timeLimit <- asks getTimeLimit
+ let timeRemaining = timeLimit - (timeOf here)
+ cf <- currentFlow here
+ let closedValves = (cave `M.withoutKeys` (here ^. dOpenValves)) ^.. folded . flowRate
+ let sortedClosedValves = fmap sum $ chunksOf 2 $ {-# SCC estSort #-} sortOn Down closedValves
+ -- let sortedClosedValves = fmap sum $ chunksOf 2 $ reverse $ sort closedValves -- no significant improvement
+ let otherValveFlows = sum $ zipWith (*) [timeRemaining, (timeRemaining - 2) .. 0] sortedClosedValves
+ -- let otherValveFlows = timeRemaining * (sum closedValves) -- 8 minute runtime rather than 1:50
+ return $ (cf * timeRemaining) + otherValveFlows
+
+
+main :: IO ()
+main =
+ do dataFileName <- getDataFileName
+ text <- TIO.readFile dataFileName
+ let expandedCave = successfulParse text
+ -- print cave
+ -- print $ reachableFrom cave [Tunnel "AA" 0] S.empty []
+ -- print $ compress cave
+ let cave = compress expandedCave
+ print $ part1 cave
+ print $ part2 cave
+
+-- part1 :: Cave -> Maybe (Agendum SingleSearchState)
+-- part1 cave = runReader (searchCave "AA") (TimedCave cave 30)
+
+-- part2 :: Cave -> Maybe (Agendum DoubleSearchState)
+-- part2 cave = runReader (searchCave "AA") (TimedCave cave 26)
+
+part1, part2 :: Cave -> Int
+-- part1 :: Cave -> Int
+part1 cave = maybe 0 _benefit result
+ where result = runReader (searchCave "AA") (TimedCave cave 30) :: Maybe (Agendum SingleSearchState)
+part2 cave = maybe 0 _benefit result
+ where result = runReader (searchCave "AA") (TimedCave cave 26) :: Maybe (Agendum DoubleSearchState)
+
+searchCave :: SearchState s => String -> CaveContext (Maybe (Agendum s))
+searchCave startRoom =
+ do agenda <- initAgenda startRoom
+ aStar agenda S.empty
+
+initAgenda :: SearchState s => String -> CaveContext (Agenda s)
+initAgenda startID =
+ do let startState = emptySearchState startID
+ b <- estimateBenefit startState
+ return $ P.singleton b Agendum { _current = startState, _trail = Q.empty, _trailBenefit = 0, _benefit = b}
+
+aStar :: SearchState s => Agenda s -> ExploredStates s -> CaveContext (Maybe (Agendum s))
+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.findMax agenda) ++ " : foundFlow " ++ (show $ _trailBenefit $ snd $ P.findMax agenda)) False = undefined
+ -- | trace ("Peeping " ++ (show $ P.findMax agenda)) False = undefined
+ | P.null agenda = return Nothing
+ | otherwise =
+ do let (_, currentAgendum) = P.findMax agenda
+ let reached = currentAgendum ^. current
+ nexts <- candidates currentAgendum closed
+ let newAgenda = foldl' (\q a -> P.insert (_benefit a) a q) (P.deleteMax agenda) nexts
+ -- let beamAgenda = P.fromDescList $ P.take 10000 newAgenda -- agenda beam width
+ -- let beamAgenda = P.fromDescList $ P.take 5000 newAgenda -- agenda beam width
+ -- let beamAgenda = P.fromDescList $ P.take 1000 newAgenda -- agenda beam width
+ reachedGoal <- isGoal currentAgendum
+ -- let cl = (reached, currentAgendum ^. trailBenefit, Q.length $ currentAgendum ^. trail)
+ let cl = (reached, currentAgendum ^. trailBenefit)
+ if reachedGoal
+ then return (Just currentAgendum)
+ else if (cl `S.member` closed)
+ then aStar (P.deleteMax agenda) closed
+ else aStar newAgenda (S.insert cl closed)
+ -- else aStar beamAgenda (S.insert cl closed)
+
+
+candidates :: SearchState s => Agendum s -> ExploredStates s -> CaveContext (Q.Seq (Agendum s))
+candidates agendum closed =
+ do let candidate = agendum ^. current
+ let previous = agendum ^. trail
+ let prevBenefit = agendum ^. trailBenefit
+ succs <- successors candidate
+ succAgs <- mapM (makeAgendum previous prevBenefit) succs
+ -- let nonloops = Q.filter (\s -> (s ^. current, s ^. trailBenefit, Q.length $ s ^. trail) `S.notMember` closed) succAgs
+ let nonloops = Q.filter (\s -> (s ^. current, s ^. trailBenefit) `S.notMember` closed) succAgs
+ return nonloops
+
+
+agentSuccessor :: Int -> S.Set RoomID -> Int -> RoomID -> CaveContext [SingleSearchState]
+agentSuccessor now opened aTime here
+ | aTime /= now = return [SingleSearchState { _currentRoom = here, _currentTime = aTime, _sOpenValves = opened }]
+ | otherwise =
+ do cave <- asks getCave
+ timeLimit <- asks getTimeLimit
+ let remaining = S.toList $ S.filter (\t -> (t ^. tunnelTo) `S.notMember` opened) ((cave ! here) ^. tunnels)
+ let moves = [ SingleSearchState
+ { _currentRoom = (t ^. tunnelTo)
+ , _currentTime = now + (t ^. tunnelLength)
+ , _sOpenValves = opened
+ }
+ | t <- remaining
+ , now + (t ^. tunnelLength) <= timeLimit
+ ]
+ let opens = if here `S.notMember` opened && (cave ! here) ^. flowRate > 0
+ then [SingleSearchState { _currentRoom = here, _currentTime = aTime + 1, _sOpenValves = S.insert here opened }]
+ else []
+ -- let nexts = moves ++ opens
+ let nexts = if null opens then moves else opens
+ let nexts' = if null nexts
+ then [ SingleSearchState
+ { _currentRoom = here
+ , _currentTime = timeLimit
+ , _sOpenValves = opened
+ } ]
+ else nexts
+ return nexts'
+
+makeAgendum :: SearchState s => Q.Seq s -> Int -> s -> CaveContext (Agendum s)
+makeAgendum previous prevBenefit newState =
+ do predicted <- estimateBenefit newState -- (Q.length previous)
+ -- cf <- currentFlow newState
+ oldFlow <- lastFlow previous (timeOf newState)
+ let newTrail = previous |> newState
+ let incurred = prevBenefit + oldFlow
+ return Agendum { _current = newState
+ , _trail = newTrail
+ , _trailBenefit = incurred
+ , _benefit = incurred + predicted
+ }
+
+lastFlow :: SearchState s => Q.Seq s -> Int -> CaveContext Int
+lastFlow Q.Empty _ = return 0
+lastFlow (_ :|> previous) newTime =
+ do cf <- currentFlow previous
+ let dt = newTime - (timeOf previous)
+ return (cf * dt)
+
+isGoal :: SearchState s => Agendum s -> CaveContext Bool
+isGoal agendum =
+ do timeLimit <- asks getTimeLimit
+ let s = agendum ^. current
+ return $ (timeOf s) == timeLimit
+
+isFullFlow :: SearchState s => s -> CaveContext Bool
+isFullFlow state =
+ do cave <- asks getCave
+ cf <- currentFlow state
+ let ff = sumOf (folded . flowRate) cave
+ return (cf == ff)
+
+compress :: Cave -> Cave
+compress cave = M.mapWithKey (compressRoom cave) cave
+
+compressRoom :: Cave -> RoomID -> Room -> Room
+compressRoom cave here room = room & tunnels .~ t'
+ where t' = reachableFrom cave [Tunnel here 0] S.empty S.empty
+
+reachableFrom :: Cave -> [Tunnel] -> S.Set RoomID -> S.Set Tunnel -> S.Set Tunnel
+reachableFrom _ [] _ routes = routes
+reachableFrom cave (tunnel@(Tunnel here len):boundary) found routes
+ | here `S.member` found = reachableFrom cave boundary found routes
+ | otherwise = reachableFrom cave (boundary ++ (S.toList legs)) (S.insert here found) routes'
+ where exits = (cave ! here) ^. tunnels
+ exits' = S.filter (\t -> (t ^. tunnelTo) `S.notMember` found) exits
+ legs = S.map (\t -> t & tunnelLength .~ (len + 1)) exits'
+ routes' = if (len == 0) || ((cave ! here) ^. flowRate) == 0
+ then routes
+ else S.insert tunnel routes
+
+
+-- Parse the input file
+
+caveP :: Parser Cave
+valveP :: Parser (RoomID, Room)
+roomP :: Parser Room
+tunnelsP :: Parser (S.Set Tunnel)
+tunnelTextP :: Parser Text
+
+caveP = M.fromList <$> valveP `sepBy` endOfLine
+valveP = (,) <$> ("Valve " *> (many1 letter)) <*> roomP
+roomP = Room <$> (" has flow rate=" *> decimal) <*> (tunnelTextP *> tunnelsP)
+ -- where roomify v ts = Room {flowRate = v, tunnels = ts }
+tunnelsP = (S.fromList . (fmap (flip Tunnel 1))) <$> (many1 letter) `sepBy` ", "
+tunnelTextP = "; tunnels lead to valves " <|> "; tunnel leads to valve "
+
+successfulParse :: Text -> Cave
+successfulParse input =
+ case parseOnly caveP input of
+ Left _err -> M.empty -- TIO.putStr $ T.pack $ parseErrorPretty err
+ Right cave -> cave
\ No newline at end of file
projects / advent-of-code-22.git / blobdiff