3-单向链表-Scala实现

Posted 2021-02-18 help-silence

今天学习了单向链表的实现，记录一下，方便以后查看~

import util.control.Breaks._
object SingleLinkedListDemo {
  def main(args: Array[String]): Unit = {
    //创建和遍历
    val singleLinkedList = new SingleLinkedList()
    val node1 = new HeroNode(1,"宋江","及时雨")
    val node2 = new HeroNode(4,"卢俊义","玉麒麟")
    val node3 = new HeroNode(2,"吴用","智多星")
    val node4 = new HeroNode(3,"林冲","豹子头")
    singleLinkedList.addByOrder(node1)
    singleLinkedList.addByOrder(node2)
    singleLinkedList.addByOrder(node3)
    singleLinkedList.addByOrder(node3)
    singleLinkedList.addByOrder(node4)
    singleLinkedList.list()


  }

}

class SingleLinkedList{
  //创建头节点，指向该链表的头部
  val head = new HeroNode(-1,"","")


  //添加英雄到链表
  //默认加到链表的最后
  def add(heroNode: HeroNode):Unit= {
    //1.先找到链表的最后节点
    //2.最后节点指向新节点


    //因为head不能动，我们一个辅助指针来定位
    var temp = head

    breakable {
      while (true) {
        if (temp.next == null) {
          break()
        }
        temp = temp.next
      }
    }
    temp.next = heroNode
  }

  def addByOrder(heroNode: HeroNode):Unit={
    //让temp指向head
    var temp = head

    var flag = false //标识是否已经存在编号的节点
    //将temp定位到要添加节点的前一个位置
    breakable {
      while (true) {
        //判断是否已经到最后一个
        if (temp.next == null) {
          break()
        }

        if (temp.next.no == heroNode.no) {
          //说明no已经存在
          flag = true
          break()
        } else if (temp.next.no > heroNode.no) {
          //说明heronode，就添加到这
          break()
        }

        //将temp后移实现遍历
        temp = temp.next
      }
    }
    if (flag){
      printf("已经存在n0=%d 人物",heroNode.no)
      println()
    }else{
      heroNode.next = temp.next
      temp.next = heroNode
    }
  }

  //遍历单项链表
  //1.用temp遍历
  //2.判断链表是否为空，为空就退出；不为空。就遍历
  def list():Unit={
    if (isEmpty()){
      println("链表为空，无法遍历")
      return
    }

    var temp = head.next
    breakable {
      while (true) {
        //输出当前的节点的信息
        printf("no=%d name= %s nickname= %s", temp.no, temp.name, temp.nickname)
        println()
        if (temp.next == null) {
          break();
        } else {
          temp = temp.next
        }
      }
    }
  }
  def isEmpty():Boolean={
    head.next == null
  }

  //修改节点信息
  def update(heroNode: HeroNode):Unit={

    if (isEmpty()){
      println("链表为空~")
      return
    }
    //辅助指针，定位
    var temp = head.next
    //定义一个变量，表示是否找到该节点
    var flag = false
    breakable {
      while (true) {
        if (temp.no == heroNode.no) {
          flag = true
          break()
        }

        //判断temp 是不是到最后了
        if(temp.next == null){
          break()
        }

        temp = temp.next

      }
    }

    //判断
    if (flag){
      temp.name = heroNode.name
      temp.nickname = heroNode.nickname
    }else{
      printf("你要修改的%d英雄不存在",temp.no)
    }
  }


  //删除一个节点
  def delete(no:Int):Unit={
    if (isEmpty()){
      println("链表为空~")
      return
    }

    //让temp指向head
    var temp =head
    var flag = false
    //遍历，让temp指向，要删除的节点的前一个节点
    breakable {
      while (true) {
        if (temp.next.no == no) {
          flag = true
          break()
        }
    //判断temp是否指向链表的倒数第二个节点
        if (temp.next.next == null){
          break()
        }
        temp = temp.next
      }
    }

    //判断flag
    if (flag){
      //找到了
      temp.next = temp.next.next
    }else{
      printf("要删除的节点%d 不存在",no)
    }

  }

}


class HeroNode(hNO:Int,hName:String,hNickname:String){

  val no = hNO
  var name = hName
  var nickname = hNickname
  var next: HeroNode =null

}