function - 这段代码有什么问题？（Scala递归的河内塔）

Question

我又需要帮助了。我不知道这段代码有什么问题，有人可以帮助我吗？

def moveTower(n: Int, source: Stack[Int], sink: Stack[Int], workspace: Stack[Int]):     Stack[Int] = {
    if (n == 1) {
      sink.push(source.pop.##)
    } else {
      moveTower(n - 1, source, workspace, sink)
      sink.push(source.pop.##)
      moveTower(n - 1, workspace, sink, source)
    }
  }

  var source = Stack[Int](5, 4, 3, 2, 1)
  var sink = Stack[Int]()
  var workspace = Stack[Int]()
  moveTower(source.length.toInt, source, sink, workspace)
  println(source, sink, workspace)

Answer 1

排队：

  println(moveTower(n, source, sink, workspace))

注意moveTower()type 是 Unit 它的 printUnit.toString