X-Git-Url: https://git.njae.me.uk/?a=blobdiff_plain;f=adventofcode16%2Fapp%2Fadvent07.hs;fp=adventofcode16%2Fapp%2Fadvent07.hs;h=870095855e8eac5cbc5bbe09cd27358d44e02236;hb=fd498a2713d69a5d55179ff07e58ce296d6fba94;hp=0000000000000000000000000000000000000000;hpb=3a26b187d5dc23b05fb73daabe52a92976a7a3c7;p=advent-of-code-16.git

diff --git a/adventofcode16/app/advent07.hs b/adventofcode16/app/advent07.hs
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+module Main(main) where
+
+import Text.Parsec
+import Data.List (partition, union, intersect, tails)
+import Data.Char (isAlphaNum)
+
+data Chunk = Include String | Exclude String deriving (Show)
+data ChunkV = Includev Bool | Excludev Bool deriving (Show)
+
+chunkValue :: Chunk -> String
+chunkValue (Include v) = v
+chunkValue (Exclude v) = v
+
+isInclude :: Chunk -> Bool
+isInclude (Include _) = True
+isInclude (Exclude _) = False
+
+chunkValueV :: ChunkV -> Bool
+chunkValueV (Includev v) = v
+chunkValueV (Excludev v) = v
+
+isIncludeV :: ChunkV -> Bool
+isIncludeV (Includev _) = True
+isIncludeV (Excludev _) = False
+
+
+main :: IO ()
+main = do 
+    text <- readFile "data/advent07.txt" 
+    part1 text
+    part2 text
+
+
+part1 :: String -> IO ()
+part1 text = do 
+    print $ length $ filter (allowsAbba) $ successfulParse $ parseI7vf text
+
+
+part2 :: String -> IO ()
+part2 text = do 
+    print $ length $ filter (supportsSSL) $ successfulParse $ parseI7f text
+
+allowsAbba :: [ChunkV] -> Bool
+allowsAbba chunks = (any (chunkValueV) includeChunks) && (not (any (chunkValueV) excludeChunks))
+    where (includeChunks, excludeChunks) = partition (isIncludeV) chunks
+
+i7file = i7line `endBy` newline 
+i7line = many1 (includeChunk <|> excludeChunk)
+
+chunk = many1 alphaNum
+
+excludeChunk = Exclude <$> (between (char '[') (char ']') $ chunk)
+includeChunk = Include <$> chunk
+
+hasABBA = preambleAbba <* (many alphaNum)
+preambleAbba = (try abba) <|> (alphaNum >> preambleAbba)
+
+-- abba = 
+--     do  a <- alphaNum
+--         b <- alphaNum
+--         if a == b then
+--             fail "Identical"
+--         else do char b
+--                 char a
+--                 return [a, b, b, a]
+
+abba = 
+    do  a <- alphaNum
+        b <- noneOf [a]
+        char b
+        char a
+        return [a, b, b, a]
+
+--         where
+--   firstChar = satisfy (\a -> isLetter a || a == '_')
+--   nonFirstChar = satisfy (\a -> isDigit a || isLetter a || a == '_')
+
+   -- b <- bChar
+-- where bChar = satisfy (\l -> lsLetter l && l /= a)
+
+
+
+i7filev = i7linev `endBy` newline
+i7linev = many1 (includeChunkv <|> excludeChunkv)
+
+excludeChunkv = Excludev <$> (between (char '[') (char ']') $ hasABBAv)
+includeChunkv = Includev <$> hasABBAv
+
+hasABBAv = 
+    (try (id True <$ preambleAbba <* (many alphaNum)))
+    <|>
+    (id False <$ (many1 alphaNum))
+
+
+parseI7f :: String -> Either ParseError [[Chunk]]
+parseI7f input = parse i7file "(unknown)" input
+
+parseI7 :: String -> Either ParseError [Chunk]
+parseI7 input = parse i7line "(unknown)" input
+
+parseAbba :: String -> Either ParseError String
+parseAbba input = parse hasABBA "(unknown)" input
+
+parseI7v :: String -> Either ParseError [ChunkV]
+parseI7v input = parse i7linev "(unknown)" input
+
+parseI7vf :: String -> Either ParseError [[ChunkV]]
+parseI7vf input = parse i7filev "(unknown)" input
+
+successfulParse :: Either ParseError [a] -> [a]
+successfulParse (Left _) = []
+successfulParse (Right a) = a
+
+
+allSubstrings :: Int -> [a] -> [[a]]
+-- allSubstrings n es 
+--     | length es < n = []
+--     | otherwise = (take n es) : (allSubstrings n $ tail es)
+allSubstrings n e = filter (\s -> length s == n) $ map (take n) $ tails e
+
+
+ieCandidates :: [Chunk] -> ([String], [String])
+ieCandidates chunks = (includeCandidates, excludeCandidates)
+    where (includeChunks, excludeChunks) = partition (isInclude) chunks
+          isABA s = (s!!0 == s!!2) && (s!!0 /= s!!1)
+          candidates = (filter (isABA)) . (foldl (union) []) . (map ((allSubstrings 3) . chunkValue))
+          includeCandidates = candidates includeChunks
+          excludeCandidates = candidates excludeChunks
+          
+inverseABA :: String -> String
+inverseABA s = [s!!1, s!!0, s!!1]
+
+supportsSSL :: [Chunk] -> Bool
+supportsSSL chunks = not $ null $ intersect abas eabas
+    where (abas, babs) = ieCandidates chunks
+          eabas = map (inverseABA) babs