public class LinkList<T> {// 定义一个内部类Node,Node实例代表链表的节点private class Node {// 保存节点的数据private T data;// 指向下个节点的引用private Node next;// 无参数的构造器public Node() {}// 初始化全部属性的构造器public Node(T data, Node next) {this.data = data;this.next = next;}}// 保存该链表的头节点private Node header;// 保存该链表的尾节点private Node tail;// 保存该链表中已包含的节点数private int size;// 创建空链表public LinkList() {// 空链表，header和tail都是nullheader = null;tail = null;}// 以指定数据元素来创建链表，该链表只有一个元素public LinkList(T element) {header = new Node(element, null);// 只有一个节点，header、tail都指向该节点tail = header;size++;}// 返回链表的长度public int length() {return size;}// 获取链式线性表中索引为index处的元素public T get(int index) {return getNodeByIndex(index).data;}// 根据索引index索引获取指定位置的节点private Node getNodeByIndex(int index) {if (index < 0 || index > size - 1) {throw new IndexOutOfBoundsException("线性表索引越界");}// 从header节点开始Node current = header;for (int i = 0; i < size && current != null; i++, current = current.next) {if (i == index) {return current;}}return null;}//查找链式线性表中指定元素的索引public int locate(T element) {// 从头节点开始搜索Node current = header;for (int i = 0; i < size && current != null; i++, current = current.next) {if (current.data.equals(element)) {return i;}}return -1;}// 向线性链式表的指定位置插入一个元素public void insert(T element, int index) {if (index < 0 || index > size) {throw new IndexOutOfBoundsException("线性表索引越界");}// 如果是空链表if (header == null) {add(element);} else {// 当index为0时，链表头处插入if (index == 0) {addAtHeader(element);} else {// 获取插入点的前一个节点Node prev = getNodeByIndex(index - 1);// 让prev的next指向新节点，让新节点的next引用指向原来prev的下一个节点prev.next = new Node(element, prev.next);size++;}}}// 采用尾插法为链表添加新节点public void add(T element) {// 如果该链表还是空链表if (header == null) {header = new Node(element, null);tail = header;} else {// 创建新节点Node newNode = new Node(element, null);// 让尾节点的next指向新增的节点tail.next = newNode;//以新节点作为新的尾节点tail = newNode;}size++;}// 采用头插法为链表添加新节点public void addAtHeader(T element) {// 创建新节点，让新节点的next指向原来的header，并以新节点作为新的headerheader = new Node(element, header);// 如果插入之前是空链表if (tail == null) {tail = header;}size++;}// 删除链式线性表中指定索引处的元素public T delete(int index) {if (index < 0 || index > size - 1) {throw new IndexOutOfBoundsException("线性表索引越界");}Node del = null;// 如果被删除的是header节点if (index == 0) {del = header;header = header.next;} else {// 获取删除点的前一个节点Node prev = getNodeByIndex(index - 1);// 获取将要被删除的节点del = prev.next;// 让被删除节点的next指向被删除节点的下一个节点prev.next = del.next;// 将被删除节点的的next引用del.next = null;}size--;return del.data;}// 删除链式线性表中最后一个元素public T remove() {return delete(size - 1);}// 判断链式线性表是否为空表public boolean empty() {return size == 0;}// 清空线性表public void clear() {header = null;tail = null;size = 0;}public String toString() {if (empty()) {return "[]";} else {StringBuilder sb = new StringBuilder("[");for (Node current = header; current != null; current = current.next) {sb.append(current.data.toString() + ", ");}int len = sb.length();return sb.delete(len - 2, len).append("]").toString();}}
}

public class LinkListTest {public static void main(String[] args) {LinkList<String> list = new LinkList<String>();list.insert("aaaa", 0);list.add("bbbb");list.add("cccc");list.insert("dddd", 1);System.out.println("链式线性表中插入元素后列表：" + list.toString());list.delete(2);System.out.println("链式线性表中删除元素后列表：" + list.toString());System.out.println("cccc在链表中的位置：" + list.locate("cccc"));System.out.println("链式线性表中索引2处的元素：" + list.get(2));}
}