下面的代码包括了单向链表的逆序打印
和将链表逆序,即将链表中的节点逆序连接
节点的插入(order by)
节点的删除
单链表的反转
逆序打印
利用栈的数据结构特点,遍历链表,将每个节点压入链表中,然后逐个弹出打印
package com.whb.linkedlisk;
import java.util.Stack;
public class SingleLinkedListDemo {
public static void main(String[] args) {
HeroNode h3 = new HeroNode(3, "周瑜", "火");
HeroNode h1 = new HeroNode(1, "小乔", "扇子");
HeroNode h2 = new HeroNode(2, "鲁班", "枪");
HeroNode h4 = new HeroNode(4, "曹操", "剑");
SingleLinkedList link = new SingleLinkedList();
link.add(h1);
link.add(h4);
link.add(h3);
link.add(h2);
// link.addByOrder(h4);
// link.addByOrder(h1);
// link.addByOrder(h3);
// link.addByOrder(h2);
link.list();
System.out.println();
// 测试逆序打印
reversePrint(link.getHead());
// System.out.println();
//
// HeroNode newH = new HeroNode(2, "小鲁", "手");
// link.update(newH);
//
// link.list();
// System.out.println();
//
// link.del(1);
// link.del(4);
// link.del(5);
// link.del(2);
// link.list();
// System.out.println();
//
// // 测试单链表的反转
// reverseList(link.getHead());
// link.list();
}
public static void reversePrint(HeroNode head){
Stack<HeroNode> stack = new Stack<>();
HeroNode temp = head.next;
while (true){
if (temp==null){
break;
}
stack.add(temp);
temp = temp.next;
}
while (stack.size()>0){
System.out.println(stack.pop());
}
}
/**
* 单链表反转
* @param head
*/
public static void reverseList(HeroNode head){
if(head.next==null || head.next.next==null){
return;
}
HeroNode cur = head.next;
HeroNode next = cur;
HeroNode reverseHead = new HeroNode(0, "", "");
while (true){
if(next==null){
break;
}
next = cur.next;
cur.next = reverseHead.next;
reverseHead.next = cur;
cur = next;
}
head.next = reverseHead.next;
}
}
class SingleLinkedList{
private HeroNode head = new HeroNode(0, "", "");
public HeroNode getHead(){
return head;
}
/**
* 添加到末尾
* @param heroNode
*/
public void add(HeroNode heroNode){
HeroNode temp = head;
while (true){
if(temp.next==null){
break;
}
temp = temp.next;
}
temp.next = heroNode;
}
/**
* 通过Hero的编号顺序插入到链表中
* @param heroNode
*/
public void addByOrder(HeroNode heroNode){
HeroNode temp = head;
while (true){
if(temp.next==null){
break;
}else if(temp.next.no > heroNode.no){
// 找到要插入的位置
break;
}else if (temp.next.no == heroNode.no){
System.out.println("当前插入英雄的标号为:"+heroNode.no+" 编号已经存在, 插入失败");
return;
}
temp = temp.next;
}
heroNode.next = temp.next;
temp.next = heroNode;
}
/**
* 修改
* @param newHeroNode
*/
public void update(HeroNode newHeroNode){
HeroNode temp = head.next;
while (true){
if(temp == null){
System.out.println("未找到要修改的节点");
return;
}
if(temp.no == newHeroNode.no){
break;
}
temp = temp.next;
}
temp.name = newHeroNode.name;
temp.arms = newHeroNode.arms;
}
/**
* 从链表中删除某节点
* @param no
*/
public void del(int no){
HeroNode temp = head;
while (true){
if(temp.next==null){
System.out.println("未找到要删除的节点");
return;
}
if(temp.next.no==no){
break;
}
temp = temp.next;
}
temp.next = temp.next.next;
}
public void list(){
if(head.next==null){
System.out.println("链表为空");
return;
}
HeroNode temp = head.next;
while (true){
if(temp==null){
break;
}
System.out.println(temp);
temp = temp.next;
}
}
}
class HeroNode{
public int no;
public String name;
public String arms;
public HeroNode next;
public HeroNode(int no, String name, String arms){
this.no = no;
this.name = name;
this.arms = arms;
}
@Override
public String toString() {
return "no:" + no +" Hero:" + name + " arms:" + arms;
}
}
双向链表
package com.whb.linkedlisk;
public class DoubleLinkedListDemo {
public static void main(String[] args) {
HeroNode2 h3 = new HeroNode2(3, "周瑜", "火");
HeroNode2 h1 = new HeroNode2(1, "小乔", "扇子");
HeroNode2 h2 = new HeroNode2(2, "鲁班", "枪");
HeroNode2 h4 = new HeroNode2(4, "曹操", "剑");
DoubleLinkedList link = new DoubleLinkedList();
// link.add(h1);
// link.add(h4);
// link.add(h3);
// link.add(h2);
link.addByOrder(h4);
link.addByOrder(h1);
link.addByOrder(h3);
link.addByOrder(h2);
link.update(new HeroNode2(4, "小曹", "刀"));
// link.del(3);
// link.del(1);
// link.del(4);
// link.del(2);
link.list();
}
}
class DoubleLinkedList{
private HeroNode2 head = new HeroNode2(0, "", "");
public HeroNode2 getHead(){
return head;
}
// 双向链表的遍历
public void list(){
if(head.next==null){
System.out.println("链表为空");
return;
}
HeroNode2 temp = head.next;
while (true){
if(temp==null){
break;
}
System.out.println(temp);
temp = temp.next;
}
}
// 添加一个元素到双向链表的最后
public void add(HeroNode2 heroNode2){
HeroNode2 temp = head;
while (true){
if (temp.next==null){
break;
}
temp = temp.next;
}
temp.next = heroNode2;
heroNode2.pre = temp;
}
// 顺序添加
public void addByOrder(HeroNode2 heroNode){
HeroNode2 temp = head.next;
if(temp==null){
head.next = heroNode;
heroNode.pre = head;
return;
}
while (true){
if(temp.no > heroNode.no){
// 找到要插入的位置
temp.pre.next = heroNode;
heroNode.pre = temp.pre;
heroNode.next = temp;
temp.pre = heroNode;
break;
}else if (temp.no == heroNode.no){
System.out.println("当前插入英雄的标号为:"+heroNode.no+" 编号已经存在, 插入失败");
return;
}else if(temp.next==null){
temp.next = heroNode;
heroNode.pre = temp;
break;
}
temp = temp.next;
}
}
// 修改
public void update(HeroNode2 newHeroNode){
// 判断是否空
if (head.next == null) {
System.out.println("链表为空~");
return;
}
HeroNode2 temp = head.next;
while (true){
if(temp == null){
System.out.println("未找到要修改的节点");
return;
}
if(temp.no == newHeroNode.no){
break;
}
temp = temp.next;
}
temp.name = newHeroNode.name;
temp.arms = newHeroNode.arms;
}
// 删除
public void del(int no) {
// 判断当前链表是否为空
if (head.next == null) {
// 空链表
System.out.println("链表为空，无法删除");
return;
}
HeroNode2 temp = head.next;
while (true){
if(temp==null){
System.out.println("未找到要删除的节点");
return;
}
if(temp.no==no){
break;
}
temp = temp.next;
}
temp.pre.next = temp.next;
if(temp.next!=null){
temp.next.pre = temp.pre;
}
temp.pre = null;
temp.next = null;
}
}
class HeroNode2{
public int no;
public String name;
public String arms;
public HeroNode2 next;
public HeroNode2 pre;
public HeroNode2(int no, String name, String arms){
this.no = no;
this.name = name;
this.arms = arms;
}
@Override
public String toString() {
return "no:" + no +" Hero:" + name + " arms:" + arms;
}
}
环形链表解决约瑟夫问题
package com.whb.linkedlisk;
public class Josepfu {
public static void main(String[] args) {
CircleSingleLinkedList c = new CircleSingleLinkedList();
c.addBoy(5);// 加入5个小孩节点
c.showBoy();
System.out.println();
//测试一把小孩出圈是否正确
c.countBoy(1, 2);
}
}
class CircleSingleLinkedList{
private Boy first = null;
// 添加节点
public void addBoy(int nums){
Boy curBoy = null;
for(int i = 1; i<= nums; i++){
Boy boy = new Boy(i);
if(first==null){
first = boy;
first.setNext(first);
curBoy = first;
}else {
curBoy.setNext(boy);
boy.setNext(first);
curBoy = boy;
}
}
}
// 遍历
public void showBoy(){
if (first == null){
System.out.println("empty");
return;
}
Boy curBoy = first;
while (true){
System.out.printf("小孩的编号 %d \n", curBoy.getNo());
if(curBoy.getNext()==first){
break;
}
curBoy = curBoy.getNext();
}
}
// 根据用户的输入, 计算出小孩出圈的顺序
/**
*
* @param startNo 从第几个小孩开始数
* @param countNum 表示数几下
*/
public void countBoy(int startNo, int countNum){
Boy helper = first;
while (true){
// 将helper移动到first前面
if(helper.getNext()==first){
break;
}
helper = helper.getNext();
}
// 让first指针移动到第一个开始报数的小孩的节点,helper指针也跟着移动 (k - 1) 次
for (int i = 1; i <= startNo - 1; i++){
first = first.getNext();
helper = helper.getNext();
}
// first 和 helper 指针同时移动m - 1 次, 然后出圈
while (true){
// 退出条件,只剩一个
if(helper==first){
break;
}
for (int i=1; i<=countNum-1; i++){
helper = helper.getNext();
first = first.getNext();
}
System.out.printf("%d出圈\n", first.getNo());
helper.setNext(first.getNext());
first = helper.getNext();
}
System.out.println("最后的编号:"+first.getNo());
}
}
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;
}
}