day1

Makefile

@@ -0,0 +1,25 @@
+DAY = 1
+
+DIR = day$(DAY)
+
+INPUT = $(DIR)/input.txt
+
+SRC = $(shell find $(DIR) -name "main.hs" -or -name "main.zig")
+
+ifeq ($(patsubst %hs,,$(SRC)),)
+	RUNNER = runhaskell
+else
+	RUNNER = zig run
+endif
+
+
+.PHONY: run
+run: $(SRC) $(INPUT)
+	$(RUNNER) $(SRC) < $(INPUT)
+
+$(DIR):
+	mkdir -p $(DIR)
+
+$(INPUT): | $(DIR)
+	@echo on
+	curl -H @${HOME}/creds/aoc-cookie https://adventofcode.com/2022/day/$(DAY)/input > $@

day1/main.hs

@@ -0,0 +1,52 @@
+import System.IO
+import Data.List
+import Data.List.Split
+
+
+
+
+toNum' :: String -> Int
+toNum' "" = -1
+toNum' s = read s :: Int
+
+toNum :: [String] -> [Int]
+toNum = map toNum'
+
+
+groups :: [Int] -> [[Int]]
+groups = splitOn [-1]
+
+
+parseElves :: String -> [[Int]]
+parseElves = groups . toNum . lines
+
+
+elveTotals :: [[Int]] -> [Int]
+elveTotals = map sum
+
+
+
+
+topElf :: [[Int]] -> Int
+topElf = maximum . elveTotals
+
+
+
+
+sortDesc :: Ord a => [a] -> [a]
+sortDesc = sortBy (flip compare)
+
+
+top3Elves :: [[Int]] -> Int
+top3Elves = sum . take 3 . sortDesc . elveTotals
+
+
+
+
+handler :: String -> String
+handler s = (show $ topElf $ parseElves s) ++ "\n" ++
+            (show $ top3Elves $ parseElves s) ++ "\n"
+
+main :: IO ()
+main = do
+    interact handler