Advent of Code. Day 4. Part 2.

day4.elm

module Main exposing (..)

import Html exposing (text)
import Set


input : String
input =
    """pphsv ojtou brvhsj cer ntfhlra udeh ccgtyzc zoyzmh jum lugbnk
    {-- more lines... --}
    """


isValidPassPhrase : String -> Bool
isValidPassPhrase line =
    let
        wordsCount =
            line
                |> String.words
                |> List.length

        filteredCount =
            line
                |> String.words
                |> List.map (String.toList >> List.sort >> String.fromList)
                |> Set.fromList
                |> Set.size
    in
    wordsCount == filteredCount


main : Html.Html msg
main =
    input
        |> String.lines
        |> List.filter isValidPassPhrase
        |> List.length
        |> toString
        |> text