Tree Size

package tree

object Size {

  def size[A](t: Tree[A]): Int = t match {
    case Leaf(_)      => 1
    case Branch(l, r) => 1 + size(l) + size(r)
  }

  def main(args: Array[String]): Unit = {
    val tree = Branch(Leaf(1), Branch(Branch(Branch(Leaf(3), Branch(Leaf(5), Leaf(6))), Leaf(4)), Leaf(2)))
    println(size(tree))
  }
}

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