Minor refactoring - replaced all fmaps with <$> (idk why I kept using fmaps in the first place)

01.hs

@@ -8,6 +8,6 @@ halfwaySum ns =
 
 main :: IO ()
 main = do 
-    nums <- fmap (map (read . pure)) $ readFile "01.txt"
+    nums <- map (read . pure) <$> readFile "01.txt"
     print $ circularSum nums
     print $ halfwaySum nums

02.hs

@@ -10,6 +10,6 @@ divline ns =
 
 main :: IO ()
 main = do
-    grid <- fmap (map (map read . words) . lines) $ readFile "02.txt"
+    grid <- map (map read . words) . lines <$> readFile "02.txt"
     print $ sum . map (\line -> maximum line - minimum line) $ grid
     print $ sum . map divline $ grid

04.hs

@@ -6,7 +6,7 @@ isPassphraseValid ws = sort ws == (toAscList . fromList) ws
 
 main :: IO ()
 main = do
-    passphrases <- fmap (map words . lines) $ readFile "04.txt"
+    passphrases <- map words . lines <$> readFile "04.txt"
     let valids      = sum $ map (fromEnum . isPassphraseValid) passphrases
     let stillValids = sum $ map (fromEnum . isPassphraseValid . (map sort)) passphrases
     print $ valids

05.hs

@@ -15,7 +15,7 @@ getExitSteps len f (!steps, i, jumps) =
 
 main :: IO ()
 main = do
-    jumpsList <- fmap (map read . lines) $ readFile "05.txt"
+    jumpsList <- map read . lines <$> readFile "05.txt"
     let jumpsMap  = fromList $ zip [0..] jumpsList
     print $ getExitSteps (length jumpsList) (+1)                                    (0, 0, jumpsMap)
     print $ getExitSteps (length jumpsList) (\v -> if v >= 3 then v - 1 else v + 1) (0, 0, jumpsMap)

06.hs

@@ -33,5 +33,5 @@ cycles prevCount (prevBank, banks) =
 
 main :: IO ()
 main = do
-    bank <- fmap (fromList . map read . words) $ readFile "06.txt"
+    bank <- fromList . map read . words <$> readFile "06.txt"
     print $ cycles 0 (bank, empty)

07.hs

@@ -33,19 +33,17 @@ getDiffMinority ns =
 
 parseLine :: String -> (Program, (Weight, Programs))
 parseLine line =
-    let nameAndWeight : programsString : _ = splitOn ")"  line
+    let nameAndWeight : programsString : _ = splitOn  ")" line
         name          : weight         : _ = splitOn " (" nameAndWeight
         programs = discardEmpty . splitOn ", " . last . splitOn " -> " $ programsString
     in (name, (read weight, programs))
 
 getBottom :: Map Program (Weight, Programs) -> [(Program, (Weight, Programs))] -> Program
 getBottom m l = bottomName
-    where 
+    where (bottomName, _) : _ = toList $ foldr (\(name, (_, programs)) set -> 
-        (bottomName, _) : _ = toList $ foldr 
+            case programs of
-            (\(name, (_, programs)) set -> 
+                [] -> delete name set
-                case programs of
+                ps -> foldr delete set ps)
-                    [] -> delete name set
-                    ps -> foldr delete set ps)
             m l
 
 mapToTree :: Map Program (Weight, Programs) -> Program -> Tree Weight
@@ -66,7 +64,7 @@ findBalanced (Node _ forest) =
         
 main :: IO ()
 main = do
-    programsList <- fmap (map parseLine . lines) $ readFile "07.txt"
+    programsList <- map parseLine . lines <$> readFile "07.txt"
     let programsMap  = fromList  programsList
         bottomName   = getBottom programsMap programsList
         balanced     = findBalanced . cumulate $ mapToTree programsMap bottomName

08.hs

@@ -38,7 +38,6 @@ executeInstruction m (I r v s f) =
 
 main :: IO ()
 main = do
-    input <- readFile "08.txt"
+    maxima <- map (maximum . elems) . tail . scanl executeInstruction empty . map parseLine . lines <$> readFile "08.txt"
-    let maxima = map (maximum . elems) . tail . scanl executeInstruction empty . map parseLine . lines $ input
     print $ last maxima
     print $ maximum maxima

11.hs

@@ -22,6 +22,6 @@ getDistance (Coordinates x y z) =
 
 main :: IO ()
 main = do
-    coordinates <- fmap (map getCoordinates . splitOn ",") $ readFile "11.txt"
+    coordinates <- map getCoordinates . splitOn "," <$> readFile "11.txt"
     print $ getDistance $ fold coordinates
     print $ maximum . map getDistance . scanl mappend mempty $ coordinates

12.hs

@@ -9,6 +9,6 @@ parseLine str =
 
 main :: IO ()
 main = do
-    graph <- fmap (array (0, 1999) . map parseLine . lines) $ readFile "12.txt"
+    graph <- array (0, 1999) . map parseLine . lines <$> readFile "12.txt"
     print $ length $ reachable graph 0
     print $ length $ scc graph

13.hs

@@ -24,6 +24,6 @@ anyCaught firewalls delay =
 
 main :: IO ()
 main = do
-    firewalls <- fmap (map parseLine . lines) $ readFile "13.txt"
+    firewalls <- map parseLine . lines <$> readFile "13.txt"
     print $ severity firewalls
     print $ findIndex not $ map (anyCaught firewalls) [0..]

14.hs

@@ -30,7 +30,7 @@ sparseHash lengths =
     in  concat . map (printf "%08b" . foldr xor 0) . chunksOf 16 $ hashed
 
 getEdges :: Int -> (Seq Char, [Edge]) -> (Seq Char, [Edge])
-getEdges ind (str, edges) = if str ! ind == '0' then (str, edges) else
+getEdges ind se@(str, edges) = if str ! ind == '0' then se else
     let row = ind // 128
         col = ind %  128
         neighbours = [(row + 1, col    ),

16.hs

@@ -15,7 +15,7 @@ exchange x y (s, positions, swaps) =
     in  (s, insert spunX (positions ! spunY) . insert spunY (positions ! spunX) $ positions, swaps)
 
 partner  :: Char -> Char -> State -> State
-partner  p q (s, positions, swaps) =
+partner p q (s, positions, swaps) =
     (s, positions, insert p (swaps ! q) . insert q (swaps ! p) $ swaps)
 
 spin :: Int -> State -> State
@@ -37,12 +37,12 @@ applyDance :: State -> String -> String
 applyDance (s, positions, swaps) str =
     let positionsList = snd . unzip . toAscList $ positions
         swapsReversed = fromList . (uncurry $ flip zip) . unzip . toList $ swaps
-    in map (swapsReversed !) . (drop (16 - s) <++> take (16 - s)) . map (str !!) $ positionsList
+    in  map (swapsReversed !) . (drop (16 - s) <++> take (16 - s)) . map (str !!) $ positionsList
     where (f <++> g) p = f p ++ g p
 
 main :: IO ()
 main = do
-    moves <- fmap (map parseMove . splitOn ",") $ readFile "16.txt"
+    moves <- map parseMove . splitOn "," <$> readFile "16.txt"
     let ip = [0..15]; ap = ['a'..'p']
         state  = dance moves (0, fromList $ zip ip ip, fromList $ zip ap ap)
         dances = iterate (applyDance state) ap

18a.hs

@@ -66,6 +66,6 @@ recover instructions (reg, pos, freq, rec) =
 
 main :: IO ()
 main = do
-    instructions <- fmap (fromList . map parseLine . lines) $ readFile "18.txt"
+    instructions <- fromList . map parseLine . lines <$> readFile "18.txt"
     let initialState = (V.replicate 5 0, 0, 0, 0)
     print $ recover instructions initialState

18b.hs

@@ -50,43 +50,43 @@ getValue v r = case v of
 -- OPERATIONS
 
 sen :: Value -> Instruction
-sen v Zero (State p0 p1 s c) =
+sen v Zero state@(State p0 p1 s c) =
-    State p0 { 
+    state { 
-        position = position p0 + 1 
+        zero = p0 { position = position p0 + 1 }, 
-    } p1 { 
+        one  = p1 { queue = queue p1 |> getValue v (registers p0) }, 
-        queue = queue p1 |> getValue v (registers p0) 
+        stop = (fst s, False)
-    } (fst s, False) c
+    }
 sen v One state = swap . sen v Zero . swap $ state { count = count state + 1 }
 
 rcv :: Value -> Instruction
-rcv i Zero (State p0 p1 s c) =
+rcv i Zero state@(State p0 p1 s c) =
-    if S.null $ queue p0 then State p0 p1 (True, snd s) c else
+    if S.null $ queue p0 then state { stop = (True, snd s) } else
     let (que, val) = pop $ queue p0
-    in  State p0 {
+    in  state { zero = p0 {
-        registers = registers p0 // [(getIndex i, val)],
+            registers = registers p0 // [(getIndex i, val)],
-        position  = position  p0 + 1,
+            position  = position  p0 + 1,
-        queue     = que
+            queue     = que
-    } p1 s c
+        }}
     where pop q = (deleteAt 0 q, q `index` 0)
 rcv i One state = swap . rcv i Zero . swap $ state
 
 app :: (Int -> Int -> Int) -> Value -> Value -> Instruction
-app f i v Zero (State p0 p1 s c) = 
+app f i v Zero state@(State p0 p1 s c) = 
     let reg = registers p0
         ind = getIndex i
         val = getValue v reg
-    in  State p0 {
+    in  state { zero = p0 {
-        registers = reg // [(ind, reg ! ind `f` val)],
+            registers = reg // [(ind, reg ! ind `f` val)],
-        position  = position p0 + 1
+            position  = position p0 + 1
-    } p1 s c
+        }}
 app f i v One state = swap . app f i v Zero . swap $ state
 
 jgz :: Value -> Value -> Instruction
-jgz condition offset Zero (State p0 p1 s c) =
+jgz condition offset Zero state@(State p0 p1 s c) =
     let reg = registers p0
-    in State p0 {
+    in  state { zero = p0 {
-        position = position p0 + if getValue condition reg > 0 then getValue offset reg else 1
+            position = position p0 + if getValue condition reg > 0 then getValue offset reg else 1
-    } p1 s c
+        }}
 jgz condition offset One state = swap . jgz condition offset Zero . swap $ state
 
 -- PARSE
@@ -123,6 +123,6 @@ getCount instructions state =
 
 main :: IO ()
 main = do
-    instructions <- fmap (fromList . map parseLine . lines) $ readFile "18.txt"
+    instructions <- fromList . map parseLine . lines <$> readFile "18.txt"
     let initialState = (State (Program (V.replicate 5 0) 0 empty) (Program (V.replicate 5 0 // [(4, 1)]) 0 empty) (False, False) 0)
     print $ getCount instructions initialState