liang-leetCode/src/dataANDcalc/java/LinkedList/DoubleLinkedList.java

package LinkedList;

import java.util.Scanner;

public class DoubleLinkedList {

    private DoubleLinkedList.DoubleLinkedListNode head = new DoubleLinkedList.DoubleLinkedListNode(0, 0);

    public void add(DoubleLinkedListNode node){
        DoubleLinkedListNode temp = head;
        while (true) {
            if (temp.next == null){
                break;
            }
            temp = temp.next;
        }
        temp.next = node;
        node.prev = temp;
    }

    //todo 设计按照顺序插入双向链表的方法

    public void modify(DoubleLinkedListNode node){
        DoubleLinkedListNode temp = head;
        if (head.next == null){
            System.out.println("链表为空");
            return;
        }
        while (true) {
            temp = temp.next;
            if (temp == null){
                System.out.println("未找到更新的数据");
                return;
            }
            if (temp.nodeId == node.nodeId){
                temp.data = node.data;
                System.out.println("数据更新成功");
                return;
            }
        }
    }

    public void delete(int nodeId){
        DoubleLinkedListNode temp = head.next;
        if (temp == null){
            System.out.println("链表为空");
            return;
        }
        while (true) {
            if (temp == null){
                System.out.println("未找到需要删除的节点");
                return;
            }
            if (temp.nodeId == nodeId){
                if (temp.next == null){
                    temp.prev.next = null;
                    return;
                }
                temp.next.prev = temp.prev;
                temp.prev.next = temp.next;
                return;
            }
            temp = temp.next;
        }
    }

    private void show(){
        DoubleLinkedListNode temp = head;
        if (head.next == null){
            System.out.println("当前双向链表为空");
        }
        while(true){
            if (temp.next == null){
                break;
            }
            temp = temp.next;
            System.out.println(temp.print());
        }
    }

    public static void main(String[] args) {
        DoubleLinkedList doubleLinkedList = new DoubleLinkedList();
        Scanner scan = new Scanner(System.in);
        while (true) {
            System.out.println("a添加节点, s查看节点, r按顺序加入, u更新数据, d删除数据 exit退出:");
            String handle = scan.next();
            if ("exit".equals(handle)){
                break;
            }
            if ("a".equals(handle)){
                System.out.println("请输入节点编号:");
                int no = scan.nextInt();
                System.out.println("请输入节点数据:");
                int data = scan.nextInt();
                DoubleLinkedList.DoubleLinkedListNode node = new DoubleLinkedList.DoubleLinkedListNode(no,data);
                doubleLinkedList.add(node);
            }
            if ("r".equals(handle)){
                System.out.println("请输入节点编号:");
                int no = scan.nextInt();
                System.out.println("请输入节点数据:");
                int data = scan.nextInt();
                DoubleLinkedList.DoubleLinkedListNode node = new DoubleLinkedList.DoubleLinkedListNode(no,data);
            }
            if ("s".equals(handle)){
                doubleLinkedList.show();
            }
            if ("u".equals(handle)){
                System.out.println("请输入更新节点编号:");
                int no = scan.nextInt();
                System.out.println("请输入更新节点数据:");
                int data = scan.nextInt();
                DoubleLinkedList.DoubleLinkedListNode node = new DoubleLinkedList.DoubleLinkedListNode(no,data);
                doubleLinkedList.modify(node);
            }
            if ("d".equals(handle)){
                System.out.println("请输入删除节点编号:");
                int no = scan.nextInt();
                doubleLinkedList.delete(no);
            }
        }
        scan.close();
    }

    public static class DoubleLinkedListNode{
        private int nodeId;
        private int data;
        private DoubleLinkedListNode next;
        private DoubleLinkedListNode prev;

        public DoubleLinkedListNode(int nodeId, int data){
            this.nodeId = nodeId;
            this.data = data;
        }

        public int getNodeId() {
            return nodeId;
        }

        public void setNodeId(int nodeId) {
            this.nodeId = nodeId;
        }

        public int getData() {
            return data;
        }

        public void setData(int data) {
            this.data = data;
        }

        public DoubleLinkedListNode getNext() {
            return next;
        }

        public void setNext(DoubleLinkedListNode next) {
            this.next = next;
        }

        public DoubleLinkedListNode getPrev() {
            return prev;
        }

        public void setPrev(DoubleLinkedListNode prev) {
            this.prev = prev;
        }

        public String print() {
            return "DoubleLinkedListNode{" +
                    "nodeId=" + nodeId +
                    ", data=" + data +
                    ", next=" + (next == null ? "null" : String.valueOf(next.nodeId)) +
                    ", prev=" + (prev == null ? "null" : String.valueOf(prev.nodeId)) +
                    '}';
        }
    }
}