List Drop

object Drop {

  def drop[A](l: List[A], n: Int): List[A] = {
    if (n <= 0) l
    else if (n >= l.length) Nil
    else drop(l.tail, n - 1)
  }

  def main(args: Array[String]): Unit = {
    println(drop(List(1, 2, 3, 4, 5), 3))
    println(drop(List(1, 2, 3, 4, 5), 5))
    println(drop(List(1, 2, 3, 4, 5), 6))
    println(drop(Nil, 6))
    println(drop(Nil, -6))
    println(drop(List(1, 2), -6))
  }
}

 

List(4, 5)
List()
List()
List()
List()
List(1, 2)

 

posted on 2016-04-18 23:17  JonkeyGuan  阅读(352)  评论(0编辑  收藏  举报