数据结构——链表

本篇文章主要是用做代码分享。代码，注释都写得很清楚，不清楚的可以问我，如果有些不对的地方也可以提出来，以便我及时改正。

接口类

//链表接口类(使用泛型)public interface ILinkList<E> {    boolean isEmpty();  //判空    boolean isFull();   //判满    int length();   //计算链表长度    void insertAfter(Node<E> p, E x) throws Exception;  //在指定节点p后面插入新元素    void insertBefore(Node<E> p, E x);  //在指定结点p前面增加元素    void remove(Node<E> p) throws Exception;    //删除元素    int removeAll(E x); //删除结点的单链表中的数据域为x的所有结点，返回被删除结点的个数    int search(E x);    //按值查找操作    E getelement(int i) throws Exception;   //按序号查找操作    void showList();    //遍历输出    void clear();   //清空表    void insertBefore(Node<E> p,Node<E> x); //在p结点的前面插入结点x    void insertAfter(Node<E> p,Node<E> x);  //在p结点的后面插入x结点    Node<E> search2(E x);   //查找链表值为x的结点}

结点类

//结点类public class Node<E> {    private E data; //数据域    private Node<E> next;   //指针域    public Node(E data, Node<E> next) {        super();        this.data = data;        this.next = next;    }    public Node(E data) {        super();        this.data = data;    }    public Node() {        super();    }    public E getData() {        return data;    }    public void setData(E data) {        this.data = data;    }    public Node<E> getNext() {        return next;    }    public void setNext(Node<E> next) {        this.next = next;    }}

链表完成类

//单链表类public class LinkList<E> implements ILinkList<E>{    private Node<E> head;   //头指针，指向第一个结点    //构造方法    public LinkList(Node<E> head) {        super();        this.head = head;    }    public LinkList() {        super();    }    public Node<E> getHead() {        return head;    }    public void setHead(Node<E> head) {        this.head = head;    }    @Override    public boolean isEmpty() {        // 判空        return head == null;    }    @Override    public boolean isFull() {        // 判满,线性表永远不满，总有空间        return false;    }    @Override    public int length() {        // 求长度        int length = 0;        Node<E> p = head;        while(p != null){            length++;            p = p.getNext();        }        return length;    }    @Override    public void insertAfter(Node<E> p, E x) throws Exception {        // 在指定结点p后面插入数据x        Node<E> s = new Node<E>(x, p.getNext());        p.setNext(s);//      若void改为Node<E>,则增加return s;    }    @Override    public void insertBefore(Node<E> p, E x) {        // 在指定节点p前面增加数据x        Node<E> n = new Node<E>(x,p);   //创建数据域为x的新结点，并指向p        Node<E> q = head;        if(p == head)   //当p为第一个结点时            head = n;        else{            while(q != null && q.getNext() != p)                q = q.getNext();            q.setNext(n);        }    }    @Override    public void remove(Node<E> p) throws Exception {        // 删除指定结点p        Node<E> q = head;        if(p == null)   //先判断是否为空            return;        if(p == head){            head = head.getNext();            return;        }        //q遍历到p的前一个        while(q.getNext() != null && q.getNext() != p)            q = q.getNext();        if(q.getNext() == p){            q.setNext(p.getNext());            return;        }    }    @Override    public int removeAll(E x) {        // 删除结点的单链表中的数据域为x的所有结点，返回被删除结点的个数        Node<E> p = head.getNext();        Node<E> q = head;        int count = 0;        while(p != null){            if(p.getData().equals(x)){                q.setNext(p.getNext());                count++;            }else                q = p;            p = p.getNext();        }        return count;    }    @Override    public int search(E x) {        // 查找数据域为x的节点并返回下标        int count = 0;        Node<E> p = head;        while(p != null && !p.getData().equals(x)){            p = p.getNext();            count++;        }        if(p == null)            return -1;        return count;    }    @Override    public E getelement(int i) throws Exception {        // 按序号查找数据操作        Node<E> p = head;        int j = 0;        while(p != null && j < i){            p = p.getNext();            j++;        }        if(j > i || p == null)            throw new Exception("第" + j + "个元素不存在！");        return p.getData();    }    @Override    public void showList() {        // 遍历输出        Node<E> p = head;        while(p != null){            System.out.print(p.getData() + " ");            p = p.getNext();        }        System.out.println();    }    @Override    public void clear() {        // 清空表        head = null;    }    @Override    public void insertBefore(Node<E> p, Node<E> x) {        // 在p结点的前面插入结点x        if (p==head){            head=x;            x.setNext(p);            return;        }        Node<E> q=head;         while(q.getNext()!=null&&q.getNext()!=p){            q=q.getNext();        }        //查找成功时， q为p的前一个结点        if (q.getNext()==p){//可能有不存在结点p的情况，如果存在，则进行下面的处理            q.setNext(x);            x.setNext(p);        }    }    @Override    public void insertAfter(Node<E> p, Node<E> x) {        // 在p结点的后面插入x结点        x.setNext(p.getNext());        p.setNext(x);    }    @Override    public Node<E> search2(E x) {        // 查找链表值为x的结点        Node<E> p = head;        while (p != null && !p.getData().equals(x)) {            p = p.getNext();        }        return p;    }}

测试类

public class TestLinkList01 {    public static void main(String[] args) throws Exception {        final int LENGTH = 5;   //链表的初始长度        LinkList<Integer> link = new LinkList<Integer>();        //创建由随机数构成的链表        Node<Integer> p = new Node<Integer>((int)(Math.random()*LENGTH)+1);        link.setHead(p);        for(int i = 1; i < LENGTH; i++){            Node<Integer> x = new Node<Integer>((int)(Math.random() * LENGTH) + 1);            p.setNext(x);            p = x;        }        link.showList();        System.out.println("表中数据长度是：" + link.length());        System.out.println(link.isEmpty());        System.out.println(link.isFull());        System.out.println(link.search(2));        int x = 2;        Object q = link.getelement(x);        System.out.println("下标为2的数据是：" + q);//      if (p!=null){//          //显示该结点及后继结点的数据//          System.out.println("查找结果:"+p.getData()+"--->"+(p.getNext()==null?"":p.getNext().getData()));//          //删除此结点//          link.remove(p);//          System.out.println("删除结点后:");//          link.showList();//      }        Node<Integer> s = new Node<Integer>(508,p.getNext());        link.insertAfter(p, s);        link.showList();        link.remove(p);        link.showList();        link.clear();        link.showList();    }}

范例一

public class PhoneNumber {    private String company;    private String phone;    public PhoneNumber(String company, String phone) {        super();        this.company = company;        this.phone = phone;    }    public PhoneNumber() {        super();    }    public String getCompany() {        return company;    }    public void setCompany(String company) {        this.company = company;    }    public String getPhone() {        return phone;    }    public void setPhone(String phone) {        this.phone = phone;    }    @Override    public String toString() {        return "[company=" + company + ", phone=" + phone + "]";    }    @Override    public boolean equals(Object p) {        return this.company.equals(((PhoneNumber)p).getCompany());    }}

范例一测试类

import java.util.Scanner;public class TestLinkList02 {    public static void main(String[] args){        final int LEN=5;        Scanner sc=new Scanner(System.in);        LinkList<PhoneNumber> phoneLink=new LinkList<PhoneNumber>();        System.out.println("请输入第1个结点的数据(PhoneNum类型):");        Node<PhoneNumber> p=new Node<PhoneNumber>(new PhoneNumber(sc.next(),sc.next()));        phoneLink.setHead(p);               for(int i=1;i<LEN;i++){            System.out.println("请输入第"+(i+1)+"个结点的数据(PhoneNum类型):");            Node<PhoneNumber> x=new Node<PhoneNumber>(new PhoneNumber(sc.next(),sc.next()));            p.setNext(x);            p=x;                    }        phoneLink.showList();        phoneLink.insertBefore(phoneLink.getHead(), new Node(new PhoneNumber("星星","400-578345")));        System.out.println("表中共有"+phoneLink.length()+"个企业的信息.");        phoneLink.showList();        p=phoneLink.search2(new PhoneNumber("星星",null));        if (p!=null){            System.out.println("查找结果："+p.getData().getPhone());        }else            System.out.println("未找到企业名称为星星的信息.");    }}