Add 2019 day 1 and 2

y2019/src/Day1.hs

@@ -0,0 +1,24 @@
+module Day1
+  ( day1
+  ) where
+
+massFuelReq :: Integer -> Integer
+massFuelReq mass = (floor (fromIntegral mass / 3)) - 2
+
+moduleFuelReq :: Integer -> Integer
+moduleFuelReq mass
+  | req > 0 =  req + moduleFuelReq req
+  | req <= 0 = 0
+  where req = massFuelReq mass
+
+day1 :: IO ()
+day1 = do
+  putStrLn "AoC 2019 day 1"
+  putStr "Enter input >"
+  input <- getContents
+  putStrLn ""
+  let modules = (map read (lines input))
+  putStrLn "Part 1"
+  print (sum (map massFuelReq modules))
+  putStrLn "Part 2"
+  print (sum (map moduleFuelReq modules))

y2019/src/Day2.hs

@@ -0,0 +1,57 @@
+module Day2
+  ( day2,
+    processInput
+  ) where
+
+import Data.List.Split
+
+replaceNth :: Int -> a -> [a] -> [a]
+replaceNth _ _ [] = []
+replaceNth n newVal (x:xs)
+  | n == 0 = newVal:xs
+  | otherwise = x:replaceNth (n-1) newVal xs
+
+processInput :: [Int] -> Int -> [Int]
+processInput input index
+  | opcode == 1 = let operand1 = input !! (input !! (index + 1))
+                      operand2 = input !! (input !! (index + 2))
+                      resultIndex = input !! (index + 3)
+                      result = operand1 + operand2
+                      newInput = replaceNth resultIndex result input
+                  in processInput newInput newIndex
+  | opcode == 2 = let operand1 = input !! (input !! (index + 1))
+                      operand2 = input !! (input !! (index + 2))
+                      resultIndex = input !! (index + 3)
+                      result = operand1 * operand2
+                      newInput = replaceNth resultIndex result input
+                  in processInput newInput newIndex
+  | opcode == 99 = input
+  | opcode > 0 = input
+  where opcode = input !! index
+        newIndex = index + 4
+
+computeVerbNoun :: Int -> Int -> [Int] -> Int
+computeVerbNoun noun verb input = (processInput newInput 0) !! 0
+  where newInput = replaceNth 1 noun . replaceNth 2 verb $ input
+
+bruteforce :: Int -> Int -> [Int] -> Int -> Int
+bruteforce noun verb input objective
+  | result == objective = noun * 100 + verb
+  | verb == 99 = bruteforce (noun + 1) 0 input objective
+  | noun < 100 = bruteforce noun (verb + 1) input objective
+  where result = computeVerbNoun noun verb input
+
+day2 :: IO ()
+day2 = do
+  putStrLn "AoC 2019 day 2"
+  putStr "Enter input >"
+  input <- getLine
+  putStrLn ""
+  let intCodes = map (read :: String -> Int) (splitOn "," input)
+
+  putStr "Part 1: "
+  print (computeVerbNoun 12 2 intCodes)
+
+  putStr "Part 2: "
+  let objective = 19690720
+  print (bruteforce 0 0 intCodes objective)