Day 20

2023-12-20 15:06:22 +01:00
parent ec2b691e3b
commit def588730c
5 changed files with 167 additions and 0 deletions
--- a/day20/Part2.hs
+++ b/day20/Part2.hs
@@ -0,0 +1,51 @@
+module Part2 where
+
+import Commons
+import Data.Map (insert, foldr, (!), notMember, toList, keys)
+
+
+applyModule :: Modules -> String -> String -> Bool -> String -> (String, [String], Bool, Modules, Bool)
+applyModule modules final source p n
+  | notMember n modules = (n, [], True, modules, False)
+  | otherwise           =
+      let m = modules ! n
+          partFinal = n == final && p
+      in case m of
+              Broadcaster o   -> (n, o, p, modules, partFinal)
+              FlipFlop s o    -> if not p then let newFF = FlipFlop {state = not s, outputs = o}
+                                               in (n, o, not s, insert n newFF modules, partFinal)
+                                 else (n, [], s, modules, partFinal)
+              Conjonction i o -> let newC = Conjonction {inputs = insert source p i, outputs = o}
+                                     state = Data.Map.foldr (&&) True $ inputs newC
+                                 in if state then (n, o, False, insert n newC modules, n == final)
+                                    else (n, o, True, insert n newC modules, partFinal)
+
+applyModules :: Modules -> String -> String -> Bool -> [String] -> ([(String, [String], Bool)], Modules, Bool)
+applyModules modules _ _ _ [] = ([], modules, False)
+applyModules modules final source p (h: t) =
+  let (newS, outputs, newP, newModules, done) = applyModule modules final source p h
+      (result, newNewModules, newDone) = applyModules newModules final source p t
+  in ((newS, outputs, newP): result, newNewModules, done || newDone)
+
+applySteps :: Modules -> String -> [(String, [String], Bool)] -> (Modules, Bool)
+applySteps modules _ [] = (modules, False)
+applySteps modules final ((source, names, pulse): t) =
+  let (result, newModules, done) = applyModules modules final source pulse names
+      (newNewModules, newDone) = applySteps newModules final (t ++ result)
+  in (newNewModules, done || newDone)
+
+pressButton :: Modules -> String -> (Modules, Bool)
+pressButton modules final = applySteps modules final [("button", ["broadcaster"], False)]
+
+getFinalConjonction :: Modules -> String
+getFinalConjonction = fst . head . filter (\ (_, v) -> "rx" `elem` outputs v) . toList
+
+pressButtonUntilDone' :: Modules -> String -> Int -> [Int] -> [Int]
+pressButtonUntilDone' modules final i nPresses
+  | length nPresses == length (inputs (modules ! final)) = nPresses
+  | otherwise                                            =
+      let (newModules, done) = pressButton modules final
+      in pressButtonUntilDone' newModules final (i + 1) (if done then (i + 1): nPresses else nPresses)
+
+pressButtonUntilDone :: Modules -> [Int]
+pressButtonUntilDone modules = pressButtonUntilDone' modules (getFinalConjonction modules) 0 []