package example

case class Tree(val value: Int, val childs: List[Tree] = null)

object DeepestTree extends App {

  def findDeepestTree(tree: Tree): Tree = {
    def loop(subtree: Tree, acc: (Int, Tree)): (Int, Tree) =
      subtree.childs match {
        case x: List[Tree] => {
          (for (t <- x)
            yield acc._1 -> loop(t, (acc._1 + 1, subtree))
          ).maxBy(_._1)._2
        }
        case _ => acc
      }

    loop(tree, (0, tree))._2
  }

  val tree = Tree(10,
    List(Tree(5,
        List(Tree(6,
            List(Tree(9))),
        Tree(1))),
    Tree(4)))

  println(findDeepestTree(tree).value)

}