X-Git-Url: https://git.njae.me.uk/?a=blobdiff_plain;f=src%2Fadvent04%2Fadvent04.hs;fp=src%2Fadvent04%2Fadvent04.hs;h=b8ae85c8a46f885b993184c43ecc25676446ce44;hb=44f12be1a7004e39cb6e4064a335bcecf7cc728a;hp=0000000000000000000000000000000000000000;hpb=56a472b8d4126a5f146a655662d867d5c32a783a;p=advent-of-code-17.git

diff --git a/src/advent04/advent04.hs b/src/advent04/advent04.hs
new file mode 100644
index 0000000..b8ae85c
--- /dev/null
+++ b/src/advent04/advent04.hs
@@ -0,0 +1,28 @@
+import Data.List (sort)
+import Data.List.Split (splitOn)
+import qualified Data.Map.Strict as M
+
+main :: IO ()
+main = do 
+        text <- readFile "data/advent04.txt"
+        let passphrases = map parseLine $ lines text
+        print $ part1 passphrases
+        print $ part2 passphrases
+
+part1 :: [[String]] -> Int
+part1 = length . filter (not . containsDuplicates) 
+
+part2 :: [[String]] -> Int
+part2 = length . filter (not . containsAnagrams) 
+
+parseLine :: String -> [String]
+parseLine = filter (not . null) . splitOn " "    
+
+frequency :: (Ord a) => [a] -> M.Map a Int 
+frequency xs = M.fromListWith (+) [(x, 1) | x <- xs]
+
+containsDuplicates :: [String] -> Bool
+containsDuplicates = (not . M.null) . M.filter (> 1) . frequency
+
+containsAnagrams :: [String] -> Bool
+containsAnagrams = containsDuplicates . (map sort)