衍生集合

object Test12_DerivedCollection {
  def main(args: Array[String]): Unit = {
    val list = List(1, 2 ,3 ,4 ,5, 6)
    val list1 = List(1, 2, 3, 11, 22, 33)

    //1、获取集合的头
    println(list.head)

    //2、获取集合的尾（头剩下的都是尾）
    println(list.tail)

    //3、集合最后一个数据
    println(list.last)

    //4、集合初始数据（不包含最后一个）
    println(list.init)

    //5、反转
    println(list.reverse)

    //6、取前（后）n个元素
    //前
    println(list.take(3))
    //后
    println(list.takeRight(2))

    //7、去掉前（后）n个元素

    println(list.drop(2))
    println(list.dropRight(3))

    //8、并集
    val union = list.union(list1)
    println("union: " + union)

    //如果是set做并集，会去重
    val set = Set(1, 2 ,3 ,4 ,5, 6, 7)
    val set1 = Set(1, 2, 3, 11, 22, 33, 55)
    val union1 = set.union(set1)
    println("union1: " + union1)

    println("-------------------------------")

    //9、交集
    val intersection = list.intersect(list1)
    println("intersection: " +intersection)

    println("-----------------------------")

    //10、差集
    val diff = list.diff(list1)
    println("diff：" + diff)

    val diff1 = list1.diff(list)
    println("diff1: " + diff1)

    println("----------------------------------")

    //11、拉链
    println("zip: " + list.zip(list1))
    println("zip: " + list1.zip(list))

    println("----------------------------------")

    //12、滑窗
    //窗口的大小为3
   for (elem <- list.sliding(3)) println(elem)
    println("----------------------------")
    //隔两个滑窗一次
   for (elem <- list1.sliding(4, 2)) println(elem)
    println("-----------------------")
    //滚动窗口，窗口大小和相隔数相同
   for (elem <- list1.sliding(3, 3)) println(elem)
  }
}