X-Git-Url: https://git.njae.me.uk/?p=advent-of-code-20.git;a=blobdiff_plain;f=advent19%2Fsrc%2Fadvent19atto.hs;fp=advent19%2Fsrc%2Fadvent19atto.hs;h=b322324de0b9d2c3622f27cbd519f56946be10ab;hp=0000000000000000000000000000000000000000;hb=cc6239892b5dea639d6787a53bffef90a5cf2841;hpb=39598d4a19968acde767a9af7ce4cf0736062e47

diff --git a/advent19/src/advent19atto.hs b/advent19/src/advent19atto.hs
new file mode 100644
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+++ b/advent19/src/advent19atto.hs
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+-- import Debug.Trace
+
+import Data.Text (Text)
+import qualified Data.Text as T
+import qualified Data.Text.IO as TIO
+
+import Data.Attoparsec.Text 
+-- import Data.Attoparsec.Combinator
+import Control.Applicative
+-- import Control.Applicative.Combinators
+
+import qualified Data.IntMap.Strict as M
+import Data.IntMap.Strict ((!))
+import Data.Functor (void)
+import Prelude hiding (take)
+import Data.Either 
+
+
+data Rule = Letter Char 
+          -- | Then2 Rule Rule
+          -- | Then3 Rule Rule Rule
+          | Then [Rule]
+          | Or Rule Rule
+          | See Int
+          deriving (Show, Eq)
+
+-- data Tree = TEmpty
+--           | TLetter Char
+--           | TThen [Tree]
+--           deriving (Show, Eq)
+
+
+type RuleSet = M.IntMap Rule
+
+
+main :: IO ()
+main = 
+  do  text <- TIO.readFile "data/advent19b.txt"
+      -- print text
+      let (rules, messages) = successfulParse inputP text
+      let messagesT = map T.pack messages
+      -- print rules
+      -- print messages
+      print $ part1 rules messagesT
+      print $ part2 rules messagesT
+      -- print $ part2 text
+
+setup fname = 
+  do text <- TIO.readFile fname
+     let (rules, messages) = successfulParse inputP text
+     let messagesT = map T.pack messages
+     let Right newRules = parseOnly rulesP "8: 42 | 42 8\n11: 42 31 | 42 11 31"
+     let updatedRules = M.union newRules rules
+     let myParser = (makeParser updatedRules (See 0)) <* endOfInput
+     return (myParser, updatedRules, messagesT)
+
+
+
+part1 = countMatches
+
+part2 rules messages = countMatches updatedRules messages
+  where Right newRules = parseOnly rulesP "8: 42 | 42 8\n11: 42 31 | 42 11 31"
+        updatedRules = M.union newRules rules
+
+countMatches rules messages 
+  = length 
+  $ filter isRight 
+  $ map (parseOnly myParser) messages
+  where myParser = ((makeParser rules (See 0)) <* endOfInput)
+
+
+-- Generate the rules
+
+makeParser :: RuleSet -> Rule -> Parser ()
+makeParser m (Letter c) = void $ char c
+makeParser m (Then rs) = mapM_ (makeParser m) rs
+makeParser m (Or a b) = (makeParser m a) <|> (makeParser m b)
+makeParser m (See i) = makeParser m (m!i)
+
+
+-- Parse the input
+
+rulesP = M.fromList <$> ruleP `sepBy` endOfLine
+ruleP = (,) <$> decimal <* ": " <*> ruleBodyP
+ruleBodyP = choice [letterRuleP, orRuleP, thenRuleP, seeRuleP]
+
+letterRuleP = Letter <$> ("\"" *> anyChar) <* "\""
+orRuleP = Or <$> thenRuleP <* " | " <*> thenRuleP
+thenRuleP = Then <$> seeRuleP `sepBy` (string " ")
+seeRuleP = See <$> decimal
+
+
+inputP = (,) <$> rulesP <* blankLines <*> messagesP
+
+messagesP = (many1 letter) `sepBy` endOfLine
+
+blankLines = skipMany1 endOfLine
+
+
+-- successfulParse :: Text -> (Integer, [Maybe Integer])
+successfulParse parser input = 
+  case parseOnly parser input of
+    Left  _err -> (M.empty, []) -- TIO.putStr $ T.pack $ parseErrorPretty err
+    Right expressions -> expressions