X-Git-Url: https://git.njae.me.uk/?p=advent-of-code-20.git;a=blobdiff_plain;f=advent06%2Fsrc%2Fadvent06.hs;fp=advent06%2Fsrc%2Fadvent06.hs;h=9e8050108bacf47f1bae570044f78b23cf68d7a3;hp=0000000000000000000000000000000000000000;hb=c128358103fbce9ad4b7f44418f33c7f9f55f296;hpb=9ced9f211023ac567fc36b9ffd76c678685ff442

diff --git a/advent06/src/advent06.hs b/advent06/src/advent06.hs
new file mode 100644
index 0000000..9e80501
--- /dev/null
+++ b/advent06/src/advent06.hs
@@ -0,0 +1,39 @@
+-- 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 qualified Data.Set as S
+
+main :: IO ()
+main = 
+  do  text <- TIO.readFile "data/advent06.txt"
+      let groups = successfulParse text
+      -- print groups
+      print $ part1 groups
+      print $ part2 groups
+
+part1 groups = sum $ map (S.size . S.unions) groups
+part2 groups = sum $ map (S.size . intersections) groups
+
+intersections :: Ord a => [S.Set a] -> S.Set a
+intersections group = foldl S.intersection (head group) group
+
+-- -- Parse the input file
+
+blankLines = skipMany1 endOfLine
+
+personP = S.fromList <$> many1 letter
+groupP = sepBy1 personP endOfLine
+
+groupsP = sepBy1 groupP blankLines
+
+-- successfulParse :: Text -> [Passport]
+successfulParse input = 
+  case parseOnly groupsP input of
+    Left  _err -> [] -- TIO.putStr $ T.pack $ parseErrorPretty err
+    Right groups -> groups