object Main {

  private def clone_rec(root: Node, nodes_completed: HashMap[Node, Node]): Node = {

    if (root == null) return null

    val newNode = new Node(root.data)

    nodes_completed.put(root, newNode)

​

    for (p <- root.friends) {

      val x = nodes_completed(p)

      if (x == null) newNode.friends.addOne(clone_rec(p, nodes_completed))

      else newNode.friends.addOne(x)

    }

    newNode

  }

​

  def clone(root: Node): Node = {

    val nodes_completed = new HashMap[Node, Node](){override def default(key:Node):Node = null}

    clone_rec(root, nodes_completed)

  }

​

  def main(args: Array[String]): Unit = {

    val vertices = CloneGraph.createTestGraphDirected(7, 18)

​

    CloneGraph.printGraph(vertices(0))

    val cp = clone(vertices(0))

    println()

    println("After copy.")

    CloneGraph.printGraph(cp)

    val set = new HashSet[Node]()

    println(CloneGraph.are_graphs_equal_rec(vertices(0), cp, set))

  }

}

​

​

​