该部分包含以下内容
-单链表的增删改查
-计算链表长度
-逆序链表
-寻找（删除）链表倒数第K个元素
-逆序打印链表（使用栈）
import java.util.Stack;
import javax.swing.text.AbstractDocument.BranchElement;
public class SingleLinkedListDemo {
public static void main(String[] args) {
// TODO Auto-generated method stub
// 先创建节点
HeroNode hero1 = new HeroNode(1, "song", "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");
// 加入节点
// 创建链表
Singlelinkedlist singlelinkedlist = new Singlelinkedlist();
singlelinkedlist.addByOrder(hero1);
singlelinkedlist.addByOrder(hero4);
singlelinkedlist.addByOrder(hero3);
singlelinkedlist.addByOrder(hero2);
// singlelinkedlist.addByOrder(hero3);
singlelinkedlist.showList();
HeroNode newheroNode = new HeroNode(2, "小路", "玉麒麟");
singlelinkedlist.update(newheroNode);
// singlelinkedlist.showList();
// singlelinkedlist.deletenode(4);
System.out.println();
// singlelinkedlist.showList();
// System.out.println(getLength(singlelinkedlist.getHead()));
// System.out.println(findLastIndexNode(singlelinkedlist.getHead(), 1));
// 逆序链表
// reverseLinkList(singlelinkedlist.getHead());
// 逆序打印
System.out.println("********************");
reverseprintList(singlelinkedlist.getHead());
System.out.println();
singlelinkedlist.showList();
}
// 获取单链表的个数
public static int getLength(HeroNode head) {
if (head.next == null) {
return 0;
}
int length = 0;
HeroNode curHeroNode = head.next;
while (curHeroNode != null) {
length++;
curHeroNode = curHeroNode.next;
}
return length;
}
// 查找单链表的倒数第k个节点
// 接收head节点，接收k 的index
// 先把链表从头到尾遍历一下，得到链表的长度
// 再遍历size-index个节点
public static HeroNode findLastIndexNode(HeroNode head, int index) {
if (head.next == null) {
return null;
}
// 获得链表长度
int size = getLength(head);
// 检验index是否合法
if (index <= 0 || index > size) {
System.out.println("index不合法");
return null;
}
HeroNode curHeroNode = head.next;
for (int i = 1; i <= size - index; i++) {
// 走几步到倒数第K个节点
curHeroNode = curHeroNode.next;
}
return curHeroNode;
}
// 单链表反转
// 第一种方法：建立一个新链表，然后使用头插法建立链表
public static void reverseLinkList(HeroNode head) {
if (head.next == null) {
return;
}
HeroNode reverseHead = new HeroNode(0, "", "");
HeroNode curHeroNode = head.next;
HeroNode nextHeroNode = null;
while (curHeroNode != null) {
// HeroNode tmpHeroNode=curHeroNode;
nextHeroNode = curHeroNode.next;
curHeroNode.next = reverseHead.next;
reverseHead.next = curHeroNode;
curHeroNode = nextHeroNode;
}
head.next = reverseHead.next;
}
public static void showreverseList(HeroNode head) {
// 判断链表是否为空
if (head.next == null) {
return;
}
HeroNode tempHeroNode = head.next;
while (true) {
// 判断是否已经到达最后一个节点
if (tempHeroNode == null) {
break;
}
// 打印
System.out.println(tempHeroNode);
//
tempHeroNode = tempHeroNode.next;
}
}
// 逆序打印
public static void reverseprintList(HeroNode head) {
if (head.next == null) {
return;
}
// 创建一个栈，不需要自己写
Stack stack = new Stack();
HeroNode curHeroNode = head.next;
while (curHeroNode != null) {
stack.push(curHeroNode);
curHeroNode = curHeroNode.next;
}
while (stack.size() > 0) {
System.out.println(stack.pop());
}
}
}
// 定义linklist
class Singlelinkedlist {
// 初始化头节点
private HeroNode head = new HeroNode(0, "", "");
// 添加节点到单向链表
// 1.找到当前链表的最后节点
// 2.将最后的next域指向最后节点
public void addNode(HeroNode heronode) {
HeroNode tempHeroNode = head;
while (true) {
// 获取最后的节点
if (tempHeroNode.next == null) {
break;
}
tempHeroNode = tempHeroNode.next;
}
// 将最后节点的next
tempHeroNode.next = heronode;
}
// 按顺序添加节点
public void addByOrder(HeroNode heronode) {
HeroNode tmpHeroNode = head;
boolean flag = false;
while (true) {
// 如果是最后一个节点，证明需要插入到最后，直接退出
if (tmpHeroNode.next == null) {
break;
}
// 找到插入位置
if (tmpHeroNode.next.no > heronode.no) {
break;
} else if (tmpHeroNode.next.no == heronode.no) {
flag = true;
break;
}
tmpHeroNode = tmpHeroNode.next;
}
// 判断是否能够插入
if (flag) {
System.out.println("待插入节点已存在");
} else {
heronode.next = tmpHeroNode.next;
tmpHeroNode.next = heronode;
}
}
// 修改节点信息，编号不能变
// 根据节点编号修改
public void update(HeroNode newheroNode) {
// 判断链表是否为空
if (head.next == null) {
System.out.println("链表为空");
return;
}
HeroNode tmpHeroNode = head.next;
boolean flag = false;
while (true) {
if (tmpHeroNode == null) {
break;
}
if (tmpHeroNode.no == newheroNode.no) {
flag = true;
break;
}
tmpHeroNode = tmpHeroNode.next;
}
if (flag) {
tmpHeroNode.name = newheroNode.name;
tmpHeroNode.nickname = newheroNode.nickname;
} else {
System.out.printf("编号为%d的节点不存在\n", newheroNode.no);
}
}
public void showList() {
// 判断链表是否为空
if (head.next == null) {
return;
}
HeroNode tempHeroNode = head.next;
while (true) {
// 判断是否已经到达最后一个节点
if (tempHeroNode == null) {
break;
}
// 打印
System.out.println(tempHeroNode);
//
tempHeroNode = tempHeroNode.next;
}
}
// 单链表的删除
public void deletenode(int no) {
if (head.next == null) {
System.out.println("链表为空");
return;
}
// 找到需要删除节点的前一个节点。
HeroNode tmpHeroNode = head;
boolean flag = false;
while (true) {
if (tmpHeroNode.next == null) {
break;
}
if (tmpHeroNode.next.no == no) {
flag = true;
break;
}
tmpHeroNode = tmpHeroNode.next;
}
if (flag) {
tmpHeroNode.next = tmpHeroNode.next.next;
} else {
System.out.printf("编号为%d的节点不存在，无法删除\n", no);
}
}
// 获取单链表的个数，不包括头结点
/**
*
* @return 返回有效节点个数
*/
// 返回头结点
public HeroNode getHead() {
return head;
}
}
//定义单个节点
class HeroNode {
public int no;
public String name;
public String nickname;
public HeroNode next;
public HeroNode(int no, String name, String nickname) {
super();
this.no = no;
this.name = name;
this.nickname = nickname;
}
@Override
public String toString() {
return "HeroNode [no=" + no + ", name=" + name + ", nickname=" + nickname + "]";
}
}