java 链表的实现

class Node{
    Object data;
    Node next;

    public Node(){

    }

    public Node(Object data){
        this.data = data;
        this.next = null;
    }

    public void add(Node element){
        this.next = element;
    }
}

class list{
    Node head;
    int length;

    //链表创建
    public list(){
        head = null;
        length = 0;
    }

    //添加元素
    public void add(Object element){
        if (head == null){
            head = new Node(element);
            length++;
        }else{
            Node h = head;
            //遍历到最后一个元素退出循环
            while (h.next != null){
                h = h.next;
            }
            h.add(new Node(element));
            length++;

        }
    }


    //get方法
    public Object get(int x){
        if(x>length-1){
            return null;
        }

        //遍历到第x个元素然后返回
        Node h = head;
        while ( x-- != 0){
            h = h.next;
        }

        return h.data;

    }

    //set方法

    public void set(int index, Object element){
        if(index>length-1){
            return;
        }

        //遍历到第x个元素然后返回
        Node h = head;
        while ( index-- != 0){
            h = h.next;
        }

        h.data = element;

    }

    //删除
    public void delete(int x){
        if(x>length-1 || x<0){
            System.out.println("删除不成功，请输入正确下标");
            return;
        }

        if(x == 0){
            //假如删除第一个节点的话
            //他是头节点，不能直接删除直接让head指向下一个就好了
            head = head.next;
            length--;
            return;
        }


        //遍历到x的前一个元素指向下一个元素就好了
        Node h = head;

        while ( --x != 0){
            h = h.next;

        }


        //x = length-1 说明是删除最后一个元素
        if(x != length-1){
            h.next = h.next.next;
            length--;

        }else {
            h = null;
            length--;
        }

    }

    public void bianli(){

        Node h = head;
        while (h != null ){
            System.out.print(h.data+"\t");
            h = h.next;
        }

        System.out.println();
    }


}