数据结构--链表
单向链表
HeroNode节点类
package 链表;
public class HeroNode {
public int no;
public String name;
public String nickname;
public HeroNode next;//指向下一个节点
public HeroNode(int no, String name, String nickname) {
this.no = no;
this.name = name;
this.nickname = nickname;
}
@Override
public String toString() {
return "HeroNode{" +
"no=" + no +
", name='" + name + '\'' +
", nickname='" + nickname + '\'' +
'}';
}
}
链表类
package 链表;
//单向链表管理节点
public class SingleLinkedList {
//定义一个头节点
private HeroNode head=new HeroNode(0,"","");
//添加节点到单向链表最后
public void add(HeroNode heroNode){
HeroNode temp=head;
//定义一个临时变量找到链表的最后位置
while(temp.next!=null){
temp=temp.next;
}
//退出循环时即找到了最后的位置
temp.next=heroNode;
}
//添加节点到链表指定编号位置
public void addByOrder(HeroNode heroNode){
HeroNode temp=head;
//boolean flag=true;
while(true){
//temp是最后一个位置，不能插入
if(temp.next==null){
break;
}else if(temp.next.no>heroNode.no){
heroNode.next=temp.next ;
temp.next=heroNode;
break;
} else if (temp.next.no==heroNode.no){
System.out.println("插入的编号"+heroNode.no+"已经存在，插入不了！");
break;
}
temp=temp.next;
}
}
//修改节点
public void update(HeroNode newHeroNode){
//首先判断链表为空
if(head.next==null){
System.out.println("链表为空");
return;
}
//根据编号找到指定节点
HeroNode temp=head.next;
while (true){
if(temp==null){
//System.out.println("没有找到节点");
break;
}
if(temp.no==newHeroNode.no){
temp.name=newHeroNode.name;
temp.nickname=newHeroNode.nickname;
break;
}
temp=temp.next;
}
}
//删除节点
public void delete(int no){
HeroNode temp=head;
while (true){
if(temp.next==null){
break;
}
if(temp.next.no==no){
temp.next=temp.next.next;
break;
}
temp=temp.next;
}
}
//显示链表(遍历)
public void show(){
//首先判断链表为空
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;
}
}
}
测试类
package 链表;
public class SingleListDemo {
public static void main(String[] args) {
HeroNode hero1=new HeroNode(1,"宋江","及时雨");
HeroNode hero2=new HeroNode(2,"卢俊义","玉麒麟");
HeroNode hero3=new HeroNode(3,"吴用","智多星");
HeroNode hero4=new HeroNode(4,"林冲","豹子头");
SingleLinkedList singleLinkedList=new SingleLinkedList();
singleLinkedList.add(hero1);
singleLinkedList.add(hero2);
singleLinkedList.add(hero3);
singleLinkedList.add(hero4);
singleLinkedList.show();
HeroNode newheronode=new HeroNode(4,"豹子呀","是你的豹子呀~");
singleLinkedList.update(newheronode);
System.out.println("修改信息---------------------");
singleLinkedList.show();
//插入新节点到最后
HeroNode newheronode1=new HeroNode(5,"武松","是你的老虎呀~");
singleLinkedList.add(newheronode1);
System.out.println("插入新节点到最后---------------------");
singleLinkedList.show();
//插入新节点到指定位置
System.out.println("插入新节点到指定位置---------------------");
HeroNode newheronode2=new HeroNode(3,"浪青","是你的燕子呀~");
singleLinkedList.addByOrder(newheronode2);
singleLinkedList.show();
//删除节点
System.out.println("删除节点---------------------");
singleLinkedList.delete(3);
singleLinkedList.show();
//插入新节点到指定位置
System.out.println("插入新节点到指定位置---------------------");
//HeroNode newheronode2=new HeroNode(3,"浪青","是你的燕子呀~");
singleLinkedList.addByOrder(newheronode2);
singleLinkedList.show();
}
}
求单向链表中有效节点的个数
//获取节点个数
public int getLength(){
if(head.next==null){
return 0;
}
int sum=0;
HeroNode temp=head.next;
while (temp!=null){
sum++;
temp=temp.next;
}
return sum;
}
查找单链表的倒数第K个节点
//查找单链表的倒数第K个节点,就是正数第(getLength-k)个
public HeroNode numKnode(int k){
if(head.next==null){
return null;
}
int size=getLength();
HeroNode temp=head.next;
if (k<=0 || k>=size){
return null;
}
for (int i = 0; i < (size-k); i++) {
temp=temp.next;
}
return temp;
}
链表反转
//链表反转
public void reverseList(HeroNode head){
//如果链表为空或者只有一个元素节点，无需反转直接返回
if(head.next==null || head.next.next==null){
return;
}
HeroNode cur=head.next;//当前节点
HeroNode next=null;//保存当前节点的下一个节点
HeroNode reverseHead=new HeroNode(0,"","");
//遍历链表，每遍历一个节点就取出放在新链表reverseHead的最前端
while(cur!=null){
next=cur.next;
cur.next=reverseHead.next;//此时reverseHead.next=null;
reverseHead.next=cur;
cur=next;
}
head.next=reverseHead.next;
}
逆序打印链表
使用栈。
//逆序打印
public void reversePrint(HeroNode head){
while(head.next==null){
return;
}
Stack<HeroNode> stack=new Stack<HeroNode>();
HeroNode cur=head.next;
while(cur!=null){
stack.push(cur);
cur=cur.next;
}
while(stack.size()>0){
System.out.println(stack.pop());
}
}
单向环形链表
使用链表实现单环形链表
创建节点
package 链表;
public 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;
}
}
创建单向环形链表
package 链表;
public class CircleSingleLinkedList {
//当前节点
private Boy first=null;
//添加节点
public void addBoy(int nums){
if(nums<1){
System.out.println("nums的值不正确");
return;
}
//辅助指针
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
public void show(){
if(first==null){
System.out.println("无小孩节点");
return;
}
Boy curBoy=first;
while (true){
System.out.println(curBoy.getNo());
if(curBoy.getNext()==first){
break;
}
curBoy=curBoy.getNext();
}
}
}
双向链表
定义节点类
package 链表;
public class HeroNode2 {
public int no;
public String name;
public String nickname;
public HeroNode2 next;
public HeroNode2 pre;
public HeroNode2(int no, String name, String nickname) {
this.no = no;
this.name = name;
this.nickname = nickname;
}
@Override
public String toString() {
return "HeroNode2{" +
"no=" + no +
", name='" + name + '\'' +
", nickname='" + nickname + '\'' +
'}';
}
}
定义双向链表类
package 链表;
public class DoubleLinkedList {
//初始化一个头节点
private HeroNode2 head=new HeroNode2(0,"","");
//返回头节点
public HeroNode2 getHead(){
return head;
}
//遍历
public void show(){
if(head.next==null){
System.out.println("双向链表为空！");
return;
}
HeroNode2 temp=head.next;
while(temp!=null){
System.out.println(temp);
temp=temp.next;
}
}
//添加节点，默认加在最后
public void add(HeroNode2 heronode){
HeroNode2 temp=head;
while (temp.next!=null){
temp=temp.next;
}
temp.next=heronode;
heronode.pre=temp;
}
//添加节点到指定位置
public void addByOrder(HeroNode2 heroNode){
HeroNode2 temp=head;
//boolean flag=true;
while(true){
//temp是最后一个位置，不能插入
if(temp.next==null){
break;
}else if(temp.next.no>heroNode.no){
heroNode.next=temp.next ;
temp.next.pre=heroNode;
temp.next=heroNode;
heroNode.pre=temp;
break;
} else if (temp.next.no==heroNode.no){
System.out.println("插入的编号"+heroNode.no+"已经存在，插入不了！");
break;
}
temp=temp.next;
}
}
//修改节点
public void update(HeroNode2 newHeroNode){
//首先判断链表为空
if(head.next==null){
System.out.println("链表为空");
return;
}
//根据编号找到指定节点
HeroNode2 temp=head.next;
while (true){
if(temp==null){
//System.out.println("没有找到节点");
break;
}
if(temp.no==newHeroNode.no){
temp.name=newHeroNode.name;
temp.nickname=newHeroNode.nickname;
break;
}
temp=temp.next;
}
}
//删除节点
public void delete(int no){
//指针
HeroNode2 temp=head.next;
while (true){
if(temp==null){
break;
}
if(temp.no==no){
//如果是最后一个节点
if(temp.next==null){
temp.pre.next=null;
}
//不是最后一个节点
temp.pre.next=temp.next;
temp.next.pre=temp.pre;
break;
}
temp=temp.next;
}
}
}
测试
package 链表;
public class DoubleListDemo {
public static void main(String[] args) {
HeroNode2 hero1=new HeroNode2(1,"宋江","及时雨");
HeroNode2 hero2=new HeroNode2(2,"卢俊义","玉麒麟");
HeroNode2 hero3=new HeroNode2(3,"吴用","智多星");
HeroNode2 hero4=new HeroNode2(4,"林冲","豹子头");
DoubleLinkedList doubleLinkedList = new DoubleLinkedList();
doubleLinkedList.add(hero1);
doubleLinkedList.add(hero2);
doubleLinkedList.add(hero3);
doubleLinkedList.add(hero4);
//遍历
System.out.println("遍历");
doubleLinkedList.show();
System.out.println("======================");
HeroNode2 newheronode=new HeroNode2(4,"豹子呀","是你的豹子呀~");
doubleLinkedList.update(newheronode);
System.out.println("修改信息---------------------");
doubleLinkedList.show();
//插入新节点到最后
HeroNode2 newheronode1=new HeroNode2(5,"武松","是你的老虎呀~");
doubleLinkedList.add(newheronode1);
System.out.println("插入新节点到最后---------------------");
doubleLinkedList.show();
//删除节点
System.out.println("删除节点---------------------");
doubleLinkedList.delete(3);
doubleLinkedList.show();
//插入新节点到指定位置
System.out.println("插入新节点到指定位置---------------------");
HeroNode2 newheronode3=new HeroNode2(3,"浪青","是你的燕子呀~");
doubleLinkedList.addByOrder(newheronode3);
doubleLinkedList.show();
}
}