双向链表(DoubleLinkedList)

双向链表多了个Pre指针。

在链表尾部添加节点：

//add new node in the linked list end
    public void add(Node node) {
        Node temp = headNode;
        while(true) {
            if(temp.next == null) {
                temp.next = node;
                node.pre = temp;
                break;
            }else {
                temp = temp.next;
            }
        }
    }

更新节点：（此方法和单链表的更新节点方法一样）

//update node
    public void update(Node node) {
        if(headNode.next == null) {
            System.out.println("Empty double linked list!");
        }
        Node temp = headNode.next;
        boolean isFind = false;
        while(!isFind) {
            if(temp == null) {
                System.out.printf("Cannot find the node: %d",node.no);
                break;
            }
            else if(temp.no == node.no) {
                temp.name = node.name;
                isFind = true;
            }else {
                temp = temp.next;
            }
        }
    }

删除节点：

public void deleteNode(int no) {
        Node temp = headNode.next;
        if(temp ==null) {
            System.out.println("The double linked list is empty!");
        }
        boolean isFind = false;
        while(!isFind) {
            if(temp == null) {
                System.out.printf("Cannot find the node: %d",no);
                break;
            }else if(temp.no ==no) {
                temp.pre.next = temp.next;
                if(temp.next!=null) {
                    temp.next.pre = temp.pre;
                }
                isFind = true;
            }else {
                temp = temp.next;
            }
        }
    }
    

循环链表：

//show the double linked list
    public void list() {
        Node temp = headNode.next;
        if(temp == null) {
            System.out.println("The double linked list is empty!");
        }
        while(temp!=null) {
            System.out.println(temp);
            temp = temp.next;
        }
    }