Solution to Advent of Code 2022, Day 1.

Day01.elm

module Day01 exposing (partOne, partTwo)

decreasingOrder : comparable -> comparable -> Order
decreasingOrder a b =
    case compare a b of
        LT ->
            GT

        EQ ->
            EQ

        GT ->
            LT


type alias CalorieCount =
    Int


type alias ElfInventory =
    List CalorieCount


parseList : String -> List ElfInventory
parseList list =
    list
        |> String.split "\n\n"
        |> List.map (String.split "\n" >> List.filterMap String.toInt)


partOne : String -> Int
partOne input =
    input
        |> parseList
        |> List.map List.sum
        |> List.maximum
        |> Maybe.withDefault 0


partTwo : String -> Int
partTwo input =
    input
        |> parseList
        |> List.map List.sum
        |> List.sortWith decreasingOrder
        |> List.take 3
        |> List.sum