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关于单向环形链表的实际应用,先看一下下面这道题

接下来,我们先简单分析一下单向环形链表的demo 构建一个单向环形链表的思路 1)先创建第一个节点,让first指向该节点,并形成环. 2)后面当我们没创建一个节点,就把该节点,加入到已有的环形链表即可.

遍历环形链表

1)先让一个辅助指针(变量)curBoy,指向first节点 2)然后通过一个while循环遍历该环形链表即可.

package com.dataStructure.com.dataStructure.linklist;public class Josepfu {    public static void main(String[] args) {        CircleSingleLinkedList circleSingleLinkedList = new CircleSingleLinkedList();        circleSingleLinkedList.addBoy(5);        circleSingleLinkedList.showBoy();    }}//创建一个单向环形链表class CircleSingleLinkedList{    //创建first节点,当前没有编号    private Boy first = null;    //添加节点,构建成一个环形的链表    public void addBoy(int nums){        if(nums < 1){            System.out.println("nums value id incorrect");            return;        }        Boy curBoy = null;        for (int i = 1; i <= nums; i++) {            Boy boy = new Boy(i);            if(i == 1){                first = boy;                first.setNext(first);                curBoy = boy;            }else{                curBoy.setNext(boy);                boy.setNext(first);                curBoy = boy;            }        }    }    //遍历当前链表    public void showBoy(){        if(first == null){            System.out.println("linkedlist is null");            return;        }        Boy curBoy = first;        while (true){            System.out.println(curBoy.getNo());            if(curBoy.getNext() == first){                break;            }            curBoy = curBoy.getNext();        }    }}class Boy{    private int no;    private Boy next;    public Boy(int no){        this.no = no;    }    public int getNo() {        return no;    }    public void setNo(int no) {        this.no = no;    }    public Boy getNext() {        return next;    }    public void setNext(Boy next) {        this.next = next;    }    @Override    public String toString() {        return "Boy{" +                "no=" + no +                ", next=" + next +                '}';    }}

接下来将文章最开始的题解决掉,解决问题分析

(1)需求创建一个辅助指针(变量)helper,事先应该指向环形链表的最后这个节点. (2)报数之前,先让first和helper移动k-1次 (3)当报数时,让first和helper指针同时移动m-1次 (4)这时就可以将first指向小孩节点出圈 first = first.next helper.next = first

public void countBoy(int startNo,int countNo,int nums){        //先对数据进行校验        if(first == null || startNo < 1 || startNo > nums){            System.out.println("input data incorrect");            return;        }        //创建辅助指针        Boy helper = first;        //创建辅助指针helper,事先指向环形链表的最后节点        while (true){            if(helper.getNext() == first){                break;            }            helper = helper.getNext();        }        //先让first和helper移动startNo-1次        for (int i = 0; i < startNo - 1 ; i++) {            first = first.getNext();            helper = helper.getNext();        }        //first和helper同时移动countNo-1次,然后出圈        while (true){            if(helper == first){  //说明圈中只有一个节点                break;            }            for (int i = 0; i < countNo - 1 ; i++) {                first = first.getNext();                helper = helper.getNext();            }            System.out.println("出圈的是"+first.getNo());            first = first.getNext();            helper.setNext(first);        }        System.out.println("the last is" + first.getNo());    }

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