2015 Day 14 in Haskell

2015/day14/day14.hs

@@ -0,0 +1,25 @@
+import Aoc
+import Data.Bifunctor ( bimap )
+import Data.List ( sort, group )
+
+parseLine :: String -> (String, (Int, Int, Int))
+parseLine line =
+    let [name, "can", "fly", speed, "km/s", "for", flyTime, "seconds,", "but", "then", "must", "rest", "for", restTime, "seconds."] = words line in
+    (name, (read speed, read flyTime, read restTime))
+
+atTime :: Int -> (String, (Int, Int, Int)) -> (String, Int)
+atTime time (name, (s, f, r)) = (name, (*s) $ uncurry (+) $ bimap (*f) (min f) $ quotRem time (f+r))
+
+part1 :: [(String, (Int, Int, Int))] -> Int
+part1 = maximum . map (snd . atTime 2503)
+
+part2 :: [(String, (Int, Int, Int))] -> Int
+part2 reindeer = maximum $ map length $ group $ sort $ concatMap winners [1..2503]
+    where
+        winners t =
+            let distances = map (atTime t) reindeer in
+            let maxDistance = maximum $ map snd distances in
+            map fst $ filter ((==maxDistance) . snd) distances
+
+main :: IO ()
+main = aocMain (map parseLine) part1 part2