双向链表--简单的增删改查

 java简单代码：

//双向链表
public class DoubleLinkedDemo {
    public static void main(String[] args) {
        Student stu1 = new  Student(0, "苏珊", "女");
        Student stu2 = new  Student(1, "琳达", "女");
        DoubleLinked linked = new DoubleLinked();
        linked.add(stu1);
        linked.add(stu2);
        linked.findAll();
        linked.delete(0);
        linked.findAll();
        linked.update(new  Student(1, "琳达", "boy"));
        linked.findAll();
    }
    
}
class DoubleLinked{
    private Student head = new  Student(0, "", "");

    public Student getHead() {
        return head;
    }

    public void setHead(Student head) {
        this.head = head;
    }
    //add
    public void add(Student stu){
        Student temp = head;
        while(true){
            if(temp.next==null){
                break;
            }else{
                temp=temp.next;
            }
        }
        temp.next=stu;
        stu.pre=temp;
    }
    
    //findAll
    //个人理解（倒序的时候找到最后一个 然后推pre）
    public void findAll(){
        Student temp = head;
        while(true){
            if(temp.next==null && temp.pre==null){
                System.out.println("链表中没有数据");
                break;
            }
            if(temp.next==null){
                System.out.println(temp.toString());
                break;
            }else{
                if(temp.pre==null){
                    temp=temp.next;
                }else{
                    System.out.println(temp.toString());
                    temp=temp.next;
                }
            }
        }
    }
    //delete
    public void delete(int scor){
        Student temp = head;
        while(true){
            if(temp.next==null && temp.pre==null){
                System.out.println("链表中没有数据");
                break;
            }
            if(temp.pre!=null){  //判断是否是第一个
                if(temp.core==scor){
                    temp.pre.next = temp.next;
                    if(temp.next!=null){ //判断是否是最后一个
                        temp.next.pre = temp.pre;
                    }
                    break;
                }
            }
            temp=temp.next;
        }
    }
    //update
    public void update(Student stu){
        Student temp = head;
        while(true){
            if(temp.next==null && temp.pre==null){
                System.out.println("链表中没有数据");
                break;
            }
            if(temp.pre!=null){  //判断是否是第一个
                if(temp.core==stu.core){
                    temp.name = stu.name;
                    temp.sex = stu.sex;
                    break;
                }
            }
            temp=temp.next;
        }
    }
    
}
class Student{
    public int core; //排名
    public String name;
    public String sex;
    public Student pre; //上一个
    public Student next;//下一个
    
    public Student(int core, String name, String sex) {
        this.core = core;
        this.name = name;
        this.sex = sex;
    }

    @Override
    public String toString() {
        return "Student [core=" + core + ", name=" + name + ", sex=" + sex
                + "]";
    }
    
}