雙向鏈表與單鏈表區別在於他多了一個鏈域，用來存放前驅節點。

基本方法實現：

新增節點：

當前節點的next為新增節點，新增節點的next為當前節點的next.next新增節點的prior為當前結點，當前結點的prior為新增節點

刪除節點：

設置刪除節點的上一個節點為當前結點。如果當前結點的下下個節點存在的話當前結點的下一個節點為當前結點的next.next,當前結點的下一個節點的prior為當前結點，否則，當前結點的next=null

。

實現：

使用雙鏈表實現學生的新增，刪除，輸出，查找

創建學生類：student.java

package DoubleLink;

/**
 

 * @author zh
 * 學生類
 */
public class Student {
    //學號
    private int sId;
    //姓名
    private String sName;
    //年齡
    private int sAge;
    //班級
    private String className;

    public int getsId() {
        return sId;
    }

    public void setsId(int sId) {
        this.sId = sId;
    }

    public
 
 String getsName() {
        return sName;
    }

    public void setsName(String sName) {
        this.sName = sName;
    }

    public int getsAge() {
        return sAge;
    }

    public void setsAge(int sAge) {
        this.sAge = sAge;
    }

    public String getClassName() {
        return className;
    }

    
 
public void setClassName(String className) {
        this.className = className;
    }

    public Student(int sId, String sName, int sAge, String className) {
        this.sId = sId;
        this.sName = sName;
        this.sAge = sAge;
        this.className = className;
    }

    @Override
    public String toString() {
        return "student{" +
                "sId=" + sId +
                ", sName=‘" + sName + ‘\‘‘ +
                ", sAge=" + sAge +
                ", className=‘" + className + ‘\‘‘ +
                ‘}‘;
    }
}

創建節點類：DNode.java

package DoubleLink;

/**
 * @author zh
 * 雙向鏈表節點
 * 與單向鏈表節點不同的是：雙向鏈表節點多了一個鏈域，用來存放前驅節點
 */
public class DNode {

    //前驅節點
    DNode prior;
    //數據域
    Student student;
    //後繼節點
    DNode next;

    //構造頭結點
    public DNode(){
        this.prior = null;
        this.student = null;
        this.next = null;
    }

    //構造節點
    public DNode(Student student){
        this.prior = null;
        this.student = student;
        this.next = null;
    }

}

創建鏈表：DLink.java

package DoubleLink;

/**
 * 雙向鏈表
 */
public class DLink {
    //創建頭結點
    private DNode head;
    //初始化
    public DLink(){
        head = new DNode();
    }

    //新增節點
    public void addStudent(Student stu){
        DNode temp = head;
        DNode data = new DNode(stu);
        while(temp.next != null){
            temp = temp.next;
        }
        data.prior = temp;
        temp.next = data;
    }

    //有序新增
    public void addStudentBySort(Student stu){
        DNode temp = head;
        DNode node = new DNode(stu);
        while(temp.next != null){
            if(node.student.getsAge()<temp.next.student.getsAge()){
                temp.next.prior = node;
                node.next = temp.next;
                node.prior = temp;
                temp.next = node;
                return;
            }
            temp = temp.next;
        }
        node.prior = temp;
        temp.next = node;
    }

    //由前往後打印雙鏈表
    public void displayHeadToLast(){
        DNode temp = head;
        while(temp.next != null){
            System.out.println(temp.next.student);
            temp =temp.next;
        }
    }

    //獲取鏈表最後一個節點
    public DNode getLastNodeValue(DLink link){
        DNode node = null;
        DNode temp = link.head;
        if(link.head.next == null){
            return null;
        }
        while(temp.next != null){
            temp = temp.next;
        }
        node = temp;
        return node;
    }

    //刪除節點
    public void delStudent(String sName){
        DNode temp = head;
        while(temp.next != null){
            if(temp.next.student.getsName().equals(sName)){
                if(temp.next.next != null){
                    temp.next.next.prior = temp;
                    temp.next = temp.next.next;
                }else{
                    temp.next = null;
                }
                break;
            }
            temp = temp.next;
        }
    }

    public static void main(String[] args){
        DLink dLink = new DLink();

        dLink.addStudent(new Student(1,"aa",21,"1"));
        dLink.addStudent(new Student(1,"bb",20,"2"));
        dLink.addStudent(new Student(1,"cc",24,"3"));
        dLink.addStudent(new Student(1,"dd",22,"4"));

        dLink.addStudentBySort(new Student(1,"aa",21,"1"));
        dLink.addStudentBySort(new Student(2,"bb",20,"2"));
        dLink.addStudentBySort(new Student(3,"cc",24,"3"));
        dLink.addStudentBySort(new Student(4,"dd",22,"4"));

        dLink.delStudent("cc");

        dLink.displayHeadToLast();
        System.out.println();
        Student stu = dLink.getLastNodeValue(dLink).student;
        System.out.println(stu);
        System.out.println("-----------倒序輸出------------");
        //倒序輸出
        //獲取最後一個節點
        DNode node = dLink.getLastNodeValue(dLink);
        while(node.prior != null){
            System.out.println(node.student);
            node = node.prior;
        }
    }
}

java數據結構：雙向鏈表