Add 2019 day 7p1 and day 8

y2019/src/Day7.hs

@@ -0,0 +1,30 @@
+module Day7 (day7) where
+
+import Data.List
+import Intcode
+
+processProgram :: [Int] -> [Int] -> Int
+processProgram program inputs = head outputs
+  where (_, outputs) = computer inputs program [] 0
+
+chainProcesses :: [Int] -> [Int] -> Int -> Int
+chainProcesses program (phase:phases) signal
+  | null phases = newSignal
+  | otherwise = chainProcesses program phases newSignal
+  where newSignal = processProgram program [phase, signal]
+
+testCombinations :: [Int] -> [([Int], Int)]
+testCombinations program = map (\p -> (p, chainProcesses program p 0)) phasesPerm
+  where phasesPerm = permutations [0..4]
+
+day7 :: IO ()
+day7 = do
+  putStrLn $ "AoC 2019 day 7"
+  input <- getLine
+
+  let program = parseProgram input
+  let combinations = testCombinations program
+
+  let p1 = maximumBy (\(_, a) (_, b) -> compare a b) combinations
+
+  putStrLn $ "Part 1: " ++ (show p1)