bfs

bug.scala

trait Recursion[Elem] {
  val list: List[Elem] // bag
  val zero: List[Elem]

  // pasos recursivos
  def cases: PartialFunction[(List[Elem], Elem), List[Elem]]

  // cannot be overrided
  final def recursion: List[Elem] = list.foldLeft(zero) { case (acc, elem) =>
    allcases.apply((acc, elem))
  }

  private def allcases: PartialFunction[(List[Elem], Elem), List[Elem]] =
    cases.orElse { case (acc, _) => acc } // apply allcases and base case by default
}
/*
object MyRecursion extends Recursion[Int] {
  val list = List(1, 2, 3)
  val zero = Nil

  def cases = {
    case (acc, elem) if elem > 2 => acc :+ elem
  }
}
val result = MyRecursion.recursion
println(result)*/

type Value = Int
type X = Int
type Y = Int
case class Coord(x: X,y:  Y,v: Value)




object BFS extends Recursion[Coord] {
  val grid = List(
    Coord(0, 0, 0), Coord(0, 1, 0), Coord(0, 2, 0),
    Coord(1, 0, 0), Coord(1, 1, 0), Coord(1, 2, 0),
    Coord(2, 0, 0), Coord(2, 1, 0), Coord(2, 2, 0)
  )
  val list = List(Coord(0, 0, 0))
  val zero = Nil
  val visited = List(Coord(0, -1, -1))

  def cases = {
    case (acc, elem) if !visited.contains(elem) => {
      list :+ grid.filter{ item => neighboor(item, elem)} //ITS INMUTABLE HOW CAN I DO THIS OH NO
      visited :+ elem //ITS INMUTABLE HOW CAN I DO THIS OH NO
      println(list)
      acc :+ elem//WHY AM I EVEN ADDING ELEM, I NEED TO USE acc BETTER! I AM NOT USING IT FOR ALL INTENTS AND PURPOSES 
    } // MY MAYUS IS STUCK on the ON STATE, OH NO


  }


  def neighboor(a: Coord, b: Coord) : Boolean = (
         a.x + 1 == b.x
      || a.x - 1 == b.x
      || a.y + 1 == b.y
      || a.y - 1 == b.y
    )
}
val result = BFS.recursion
println(result)