Day 02

day02/Commons.hs

@@ -0,0 +1,41 @@
+module Commons where
+
+import Data.String.Utils
+import System.IO
+import Text.Read
+
+
+data Round = Round { red :: Int, green :: Int, blue :: Int }
+
+data Game = Game { gid :: Int, rounds :: [Round] }
+
+
+parseCubes :: [String] -> Round -> Round
+parseCubes [] round = round
+parseCubes ((h: ' ': 'r': 'e': 'd': []): t) round = parseCubes t round {red = read [h]}
+parseCubes ((h1: h2: ' ': 'r': 'e': 'd': []): t) round = parseCubes t round {red = read [h1, h2]}
+parseCubes ((h: ' ': 'g': 'r': 'e': 'e': 'n': []): t) round = parseCubes t round {green = read [h]}
+parseCubes ((h1: h2: ' ': 'g': 'r': 'e': 'e': 'n': []): t) round = parseCubes t round {green = read [h1, h2]}
+parseCubes ((h: ' ': 'b': 'l': 'u': 'e': []): t) round = parseCubes t round {blue = read [h]}
+parseCubes ((h1: h2: ' ': 'b': 'l': 'u': 'e': []): t) round = parseCubes t round {blue = read [h1, h2]}
+
+parseRound :: String -> Round
+parseRound roundRaw = parseCubes (split ", " roundRaw) Round {red = 0, green = 0, blue = 0}
+
+parseRounds :: String -> [Round]
+parseRounds roundsRaw = map parseRound (split "; " roundsRaw)
+
+parseGame :: String -> Game
+parseGame ('G': 'a': 'm': 'e': ' ': h: ':': ' ': t) = Game {gid = read [h], rounds = parseRounds t}
+parseGame ('G': 'a': 'm': 'e': ' ': h1: h2: ':': ' ': t) = Game {gid = read [h1, h2], rounds = parseRounds t}
+parseGame ('G': 'a': 'm': 'e': ' ': h1: h2: h3: ':': ' ': t) = Game {gid = read [h1, h2, h3], rounds = parseRounds t}
+parseGame (_: t) = parseGame t
+
+parse :: IO [Game]
+parse = do done <- isEOF
+           if done
+              then return []
+              else do line <- getLine
+                      let game = parseGame line
+                      otherGames <- parse
+                      return (game: otherGames)

day02/Main.hs

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+module Main where
+
+import Commons
+import Part1
+import Part2
+
+main = do games <- parse
+          let part1Res = sum (Part1.getPossibleIds games)
+          putStrLn (show (part1Res))
+          let part2Res = sum (Part2.getPower games)
+          putStrLn (show (part2Res))

day02/Part1.hs

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+module Part1 where
+
+import Commons
+
+
+checkRoundsPossible :: [Round] -> Bool
+checkRoundsPossible [] = True
+checkRoundsPossible (round: t) = red round <= 12 && green round <= 13 && blue round <= 14 && (checkRoundsPossible t)
+
+checkGamePossible :: Game -> Bool
+checkGamePossible Game{rounds=rounds} = checkRoundsPossible rounds
+
+getPossibleIds :: [Game] -> [Int]
+getPossibleIds [] = []
+getPossibleIds (game: t) = if (checkGamePossible game)
+                              then (gid game: getPossibleIds t)
+                              else do getPossibleIds t

day02/Part2.hs

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+module Part2 where
+
+import Commons
+
+
+getMinCubesRound :: [Round] -> Round
+getMinCubesRound (round: []) = round
+getMinCubesRound (round: otherRound: t) = getMinCubesRound (Round {red = max (red round) (red otherRound),
+                                                                   green = max (green round) (green otherRound),
+                                                                   blue = max (blue round) (blue otherRound)}: t)
+
+getPowerGame :: Game -> Int
+getPowerGame Game{rounds=rounds} = let minRound = getMinCubesRound rounds
+                                   in (red minRound) * (green minRound) * (blue minRound)
+
+getPower :: [Game] -> [Int]
+getPower [] = []
+getPower (game: t) = (getPowerGame game: getPower t)