init — add day2

day2/app/Main.hs

@@ -0,0 +1,75 @@
+module Main where
+
+import Data.List.Split (splitOn)
+
+type Red = Int
+
+type Green = Int
+
+type Blue = Int
+
+data Cube = RedQuantity Red | GreenQuantity Green | BlueQuantity Blue deriving (Show)
+
+data CubeSum = CubeSum {red :: Red, green :: Green, blue :: Blue} deriving (Show)
+
+partTwo :: [String] -> Int
+partTwo = sum . map (powerCube . makeCubes)
+
+powerCube :: [Cube] -> Int
+powerCube = getCubePower . foldr minimumSetCube CubeSum {red = 0, green = 0, blue = 0}
+
+getCubePower :: CubeSum -> Int
+getCubePower CubeSum {red = _red, green = _green, blue = _blue} = _red * _green * _blue
+
+minimumSetCube :: Cube -> CubeSum -> CubeSum
+minimumSetCube (RedQuantity q) CubeSum {red = _red, green = _green, blue = _blue} = CubeSum {red = max _red q, green = _green, blue = _blue}
+minimumSetCube (GreenQuantity q) CubeSum {red = _red, green = _green, blue = _blue} = CubeSum {red = _red, green = max _green q, blue = _blue}
+minimumSetCube (BlueQuantity q) CubeSum {red = _red, green = _green, blue = _blue} = CubeSum {red = _red, green = _green, blue = max _blue q}
+
+partOne :: [String] -> [Int]
+partOne = map fst . filter (all validate . snd) . zip [1 ..] . map makeCubes
+  where
+    validate (RedQuantity n) = n <= 12
+    validate (GreenQuantity n) = n <= 13
+    validate (BlueQuantity n) = n <= 14
+
+makeCubes :: String -> [Cube]
+makeCubes = map createCube . splitOn "," . replaceSemiColon . last . splitOn ":"
+
+replaceSemiColon :: String -> String
+replaceSemiColon = map toComma
+  where
+    toComma ';' = ','
+    toComma x = x
+
+parseElem :: String -> (String, String)
+parseElem (_ : s) = (cube, nb)
+  where
+    nb = head splited
+    cube = last splited
+    splited = splitOn " " s
+parseElem _ = undefined
+
+getElem :: (String, String) -> Cube
+getElem ("red", nb) = RedQuantity (read nb :: Red)
+getElem ("green", nb) = GreenQuantity (read nb :: Green)
+getElem ("blue", nb) = BlueQuantity (read nb :: Blue)
+getElem _ = undefined
+
+createCube :: String -> Cube
+createCube = getElem . parseElem
+
+getCubeSum :: [Cube] -> CubeSum
+getCubeSum = foldr cubeAddition CubeSum {red = 0, green = 0, blue = 0}
+
+cubeAddition :: Cube -> CubeSum -> CubeSum
+cubeAddition (RedQuantity q) CubeSum {red = _red, green = _green, blue = _blue} = CubeSum {red = _red + q, green = _green, blue = _blue}
+cubeAddition (GreenQuantity q) CubeSum {red = _red, green = _green, blue = _blue} = CubeSum {red = _red, green = _green + q, blue = _blue}
+cubeAddition (BlueQuantity q) CubeSum {red = _red, green = _green, blue = _blue} = CubeSum {red = _red, green = _green, blue = _blue + q}
+
+main :: IO ()
+main = do
+  content <- readFile "input.txt"
+  (print . sum . partOne . lines) content
+  (print . partTwo . lines) content
+  putStrLn "Yes, it works!"