Java實現單鏈表SingleLinkedList增刪改查及反轉 逆序等

//節點類
class Node {
    public int id;
    public String name;
    public Node next;

    public Node(int id, String name) {
        this.id = id;
        this.name = name;
    }

    @Override
    public String toString() {
        return "Node{" +
                "id=" + id +
                ", name='" + name + '\'' +
                '}';
    }
}

//鏈表類（管理節點）
class LinkedList {
    //頭節點
    Node head = new Node(0,null);

    //鏈表有效數據個數（鏈表長度）（頭節點不計）
    public int size(){
        Node temp = head;
        int size = 0;
        while (true){
            if (temp.next == null){
                break;
            }
            size++;
            temp = temp.next;
        }
        return size;
    }

    //展示鏈表
    public void list(){
        if (head.next == null){
            System.out.println("鏈表為空！");
            return;
        }
        Node temp = head.next;
        while (true){
            if (temp == null){
                break;
            }
            System.out.println(temp);
            temp = temp.next;
        }
    }

    //增(根據id從小到大)
    public void add(Node newNode){
        Node temp = head;
        while (true){ //用來找到鏈表尾
            if (temp.next == null) {
                break;
            }
            if (temp.id == newNode.id){
                System.out.println("要添加的節點的id已經存在，添加失敗！");
                return;
            }
            if (temp.next.id > newNode.id){
                break;
            }
            temp = temp.next;
        }
        Node node = newNode;
        newNode.next = temp.next;
        temp.next = node;
    }

    //刪(根據id匹配刪除)
    public void remove(int id){
        if (head.next == null){
            System.out.println("鏈表為空!");
            return;
        }
        Node temp = head;
        boolean flag = false; //用來標記是否找到對應id的節點
        while (true){
            if (temp.next == null){
                break;
            }
            if (temp.next.id == id){ //找到要刪除節點的前一個節點
                flag =true;
                break;
            }
            temp = temp.next;
        }
        if (flag){
            temp.next = temp.next.next;
        }else {
            System.out.println("沒有找到要刪除的節點，刪除失敗!");
        }
    }

    //改（根據id匹配要修改的節點）
    public void update(int id,String name){
        if (head.next == null){
            System.out.println("鏈表為空！");
            return;
        }
        Node temp = head;
        boolean flag = false; //用來標記是否找到對應id的節點
        while (true){
            if (temp.next == null){
                break;
            }
            if (temp.id == id){
                flag = true;
                break;
            }
            temp = temp.next;
        }
        if (flag){
            temp.name = name;
        }else {
            System.out.println("沒有找到要修改的節點，修改失敗！");
        }
    }

    //查（根據id匹配）
    public Node show(int id){
        if (head.next == null){
            System.out.println("鏈表為空！");
            return null;
        }
        Node temp = head.next;
        boolean flag = false;
        while (true){
            if (temp == null){
                break;
            }
            if (temp.id == id){
                flag = true;
                break;
            }
            temp = temp.next;
        }
        if (flag){
            return temp;
        }else {
            System.out.println("沒有找到要查找的節點，查找失敗！");
            return null;
        }
    }

    //查找倒數第n個節點
    public Node lastShow(int n){
        Node temp = head.next;
        int size = this.size();
        if (size < n || n <= 0){
            System.out.println("查找的節點不存在！");
            return  null;
        }
        for (int i = 0; i < size - n; i++) {
            temp = temp.next;
        }
        return temp;
    }

    //鏈表反轉
    public void reverse(){
        if (head.next == null || head.next.next == null){
            return;
        }
        Node reverseHead = new Node(0,null);
        Node cur = head.next; //記錄當前遍歷到的節點
        Node next = null; //記錄當前遍歷到的節點的下一個節點
        while (true){
            if (cur == null){ //確保遍歷到最後一個
                break;
            }
            next = cur.next; //保存下一個節點，避免斷鏈
            //使得反轉頭節點指向遍歷到的當前節點，而讓遍歷到的當前節點指向反轉頭節點的下一個節點
            // 確保遍歷到的當前節點始終位於反轉頭節點的下一個
            cur.next = reverseHead.next;
            reverseHead.next = cur;
            //遍歷
            cur = next;
        }
        head.next = reverseHead.next; //最後讓原頭節點指向反轉頭節點的下一個節點，即可實現原鏈表的反轉
    }

    //逆序打印
    //方法一：先反轉
    //方法二：使用棧結構
    public void reversePrint(){
        if (head.next == null){
            System.out.println("鏈表為空！");
            return;
        }
        Stack<Node> nodes = new Stack<>();
        Node temp = head.next;
        while (true){
            if (temp == null){
                break;
            }
            nodes.push(temp);
            temp = temp.next;
        }
        while (nodes.size() > 0){
            System.out.println(nodes.pop());
        }
    }
}

import java.util.Stack;

/**
 * @Author: Yeman
 * @Date: 2021-10-14-12:55
 * @Description:
 */
//測試類
public class SingleLinkedListTest {
    public static void main(String[] args) {

        LinkedList linkedList = new LinkedList();

        Node node1 = new Node(1, "阿蘭");
        Node node2 = new Node(2, "洛國富");
        Node node3 = new Node(3, "艾克森");

		//可以不按照id順序添加
        linkedList.add(node1);
        linkedList.add(node3);
        linkedList.add(node2);

        linkedList.list();

        System.out.println(linkedList.size()); //鏈表長度

//        System.out.println(linkedList.lastShow(2)); //倒數查找

//        linkedList.update(2,"張玉寧"); //改
//
//        linkedList.remove(3); //刪
//
//        System.out.println(linkedList.show(2)); //查

//        linkedList.reverse(); //鏈表反轉

        linkedList.reversePrint(); //逆序打印
        
    }
}