X-Git-Url: https://git.njae.me.uk/?p=advent-of-code-20.git;a=blobdiff_plain;f=advent04%2Fsrc%2Fadvent04.hs;fp=advent04%2Fsrc%2Fadvent04.hs;h=1960f86e38d4e68d14cc39e3fc3f303726234de6;hp=0000000000000000000000000000000000000000;hb=1949f629afb7c8d0672207bc9599c74dc19f9848;hpb=68043122bb8c2cc485dfa18d26e547ad73730a2e

diff --git a/advent04/src/advent04.hs b/advent04/src/advent04.hs
new file mode 100644
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--- /dev/null
+++ b/advent04/src/advent04.hs
@@ -0,0 +1,134 @@
+-- import Debug.Trace
+
+import Data.Text (Text)
+import qualified Data.Text as T
+import qualified Data.Text.IO as TIO
+
+import Data.Void (Void)
+
+import Text.Megaparsec hiding (State)
+import Text.Megaparsec.Char
+import qualified Text.Megaparsec.Char.Lexer as L
+import qualified Control.Applicative as CA
+
+import qualified Data.Map.Strict as M
+import qualified Data.Set as S
+import Data.Char
+import Data.List
+
+-- import Text.Megaparsec.Debug
+
+type Passport = M.Map String String
+
+requiredFields = S.fromList ["byr", "iyr", "eyr", "hgt", "hcl", 
+    "ecl", "pid"]
+expectedFields = S.union requiredFields $ S.singleton "cid"
+
+
+main :: IO ()
+main = 
+  do  text <- TIO.readFile "data/advent04.txt"
+      let passports = successfulParse text
+      -- print $ length passports
+      putStrLn $ runTests
+      print $ part1 passports
+      print $ part2 passports
+
+part1 = length . filter hasRequiredFields 
+part2 = length . filter validPassport
+
+hasRequiredFields passport = S.null $ requiredFields `S.difference` (M.keysSet passport)
+
+validPassport :: Passport -> Bool
+validPassport passport = (hasRequiredFields passport) && (all validField $ M.assocs passport)
+
+validField :: (String, String) -> Bool
+validField (key, value) =
+  case key of
+    "byr" -> validRanged 1920 2002 value
+    "iyr" -> validRanged 2010 2020 value
+    "eyr" -> validRanged 2020 2030 value
+    "hgt" -> validHeight value
+    "hcl" -> validHex value
+    "ecl" -> validEye value
+    "pid" -> validPid value
+    "cid" -> True
+    _ -> False
+
+validRanged lower upper value = 
+  if all isDigit value
+  then v >= lower && v <= upper
+  else False
+  where v = read @Int value 
+
+validHeight value = 
+  if "cm" `isSuffixOf` value
+  then validRanged 150 193 v
+  else if "in" `isSuffixOf` value
+       then validRanged 59 76 v
+       else False
+  where v = reverse $ drop 2 $ reverse value
+
+validHex value = (length value == 7) && (head value == '#') && (all isHexDigit $ tail value)
+
+validEye value = value `S.member` eyeColours
+eyeColours = S.fromList ["amb", "blu", "brn", "gry", "grn", "hzl", "oth"]
+
+validPid value = (length value == 9) && (all isDigit value)
+
+runTests :: String -- [(Text, Bool)]
+runTests = if null failures
+           then "All tests passed"
+           else show failures
+  where failures = filter failedTest testCases
+
+failedTest :: (Text, Bool) -> Bool
+failedTest (passportText, expected) = actual /= expected
+  where passport = parseTestCase passportText
+        actual = validPassport passport
+
+parseTestCase :: Text -> Passport
+parseTestCase input = 
+  case parse passportP "test" input of
+    Left  _err -> M.empty
+    Right p -> p
+
+testCases = 
+  [ ("eyr:1972 cid:100 hcl:#18171d ecl:amb hgt:170 pid:186cm iyr:2018 byr:1926", False)
+  , ("iyr:2019\nhcl:#602927 eyr:1967 hgt:170cm\necl:grn pid:012533040 byr:1946", False)
+  , ("hcl:dab227 iyr:2012\necl:brn hgt:182cm pid:021572410 eyr:2020 byr:1992 cid:277", False)
+  , ("hgt:59cm ecl:zzz\neyr:2038 hcl:74454a iyr:2023\npid:3556412378 byr:2007", False)
+  , ("pid:087499704 hgt:74in ecl:grn iyr:2012 eyr:2030 byr:1980\nhcl:#623a2f", True)
+  , ("eyr:2029 ecl:blu cid:129 byr:1989\niyr:2014 pid:896056539 hcl:#a97842 hgt:165cm", True)
+  , ("hcl:#888785\nhgt:164cm byr:2001 iyr:2015 cid:88\npid:545766238 ecl:hzl\neyr:2022", True)
+  , ("iyr:2010 hgt:158cm hcl:#b6652a ecl:blu byr:1944 eyr:2021 pid:093154719", True)
+  ]
+
+
+-- Parse the input file
+type Parser = Parsec Void Text
+
+sc :: Parser ()
+sc = L.space (skipSome (    char ' ' 
+                       <|> char '\t' 
+                       <|> (try (newline <* notFollowedBy newline))
+                       )
+             ) CA.empty CA.empty
+
+blankLines = skipSome newline
+
+symb = L.symbol sc
+colonP = symb ":"
+hashChar = char '#'
+stringP = some (alphaNumChar <|> hashChar) <* sc
+
+kvP = (,) <$> stringP <* colonP <*> stringP
+
+passportsP = passportP `sepBy` blankLines
+passportP = M.fromList <$> many kvP
+
+successfulParse :: Text -> [Passport]
+successfulParse input = 
+  case parse passportsP "input" input of
+    Left  _err -> [] -- TIO.putStr $ T.pack $ parseErrorPretty err
+    Right passports -> passports