AoC day 5

import java.security.MessageDigest

object day5 extends App {

  def digest = MessageDigest.getInstance("MD5")

  def md5(s: String): String = digest.digest(s.getBytes).map("%02x".format(_)).mkString

  def seed = "uqwqemis"

  def find = {
    def inner(n: Int, pwd: String): String = pwd match {
      case s if s.length == 8 => s
      case _ =>
        val hash = md5(seed + n)
        if (hash.take(5) == "00000") inner(n + 1, pwd + hash(5))
        else inner(n + 1, pwd)
    }
    inner(0, "")
  }

  def find2 = {
    def inner(n: Int, m: Map[Int, Char]): String = m match {
      case s if s.size == 8 => (0 to 7).map(s(_)).mkString
      case _ =>
        val hash = md5(seed + n)
        if (hash.take(5) != "00000") inner(n + 1, m)
        else {
          val key = hash(5).asDigit
          if (!m.keySet.contains(key) && key < 8) inner(n + 1, m + (key -> hash(6)))
          else inner(n + 1, m)
        }
    }

    inner(0, Map[Int, Char]())
  }

  println(find)
  println(find2)

}