scala的练习题

import scala.collection.mutable

object Test24_1 {
  def main(args: Array[String]): Unit = {
    //1
    val books=mutable.Set("朝花夕拾","活着")
    //2
    books+="三体"
    println(books)
    //3
    books-="三体"
    //4
    val rs=books.contains("Python从入门到实践")
    println(s"Python从入门到实践否存在：${rs}")
    //5
    val books2=mutable.Set("朝花夕拾","红楼梦","长歌行")
    println(books2)
    val rs2=books2.union(books)
    println(s"哪些书是他们都有的？ ${rs2}")
    val rs1=books2.intersect(books)
    println(s"哪些书是他们都有的？ ${rs1}")
    val rs3=books2.diff(books)
    println(s"哪些书是他们都有的？ ${rs3}")

  }
}