sumew

case class Window(l: Int, r: Int) {
  def size = r - l
  def ||->(i: Int): Window = this.copy(r = r + i) //widen by moving right edge right
  def |->|(i: Int): Window = this.copy(l = l + i) //shrink by moving left edge right
}

sumew

case class State[Container](current: Window, best: Window, contained: Container) {
  def lastIndex(): Int = current.r
  def firstIndex(): Int = current.l
  override def toString =
    s"current: [${current.l}, ${current.r}], best: [${best.l}, ${best.r}], excess: ${contained}"
}

sumew

trait Container[T, F[_]]

sumew

def lengthOfLongestSubstring(in: String): Int = {

  //A type alias to simplify the syntax
  type CounterContainer[T] = Map[T, Int]

  //The elements are Chars and our container, a map with the Char as key and the frequence as value holds the elements within the current window
  val longest = new SlidingWindow[Char, CounterContainer[Char]] {

    override val input: Seq[Char] = in