java 实现双向链表

双向链表是一种数据结构，每个节点包含了指向前一个节点和后一个节点的指针。在 Java 中，可以使用自定义类来实现双向链表。以下是一个简单的双向链表的实现示例：

public class DoublyLinkedList {
    private Node head;
    private Node tail;

    private class Node {
        int data;
        Node prev;
        Node next;

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

    public void addToFront(int data) {
        Node newNode = new Node(data);
        if (head == null) {
            head = newNode;
            tail = newNode;
        } else {
            newNode.next = head;
            head.prev = newNode;
            head = newNode;
        }
    }

    public void addToBack(int data) {
        Node newNode = new Node(data);
        if (head == null) {
            head = newNode;
            tail = newNode;
        } else {
            tail.next = newNode;
            newNode.prev = tail;
            tail = newNode;
        }
    }

    public void remove(int data) {
        Node current = head;
        while (current != null) {
            if (current.data == data) {
                if (current == head) {
                    head = current.next;
                    if (head != null) {
                        head.prev = null;
                    }
                } else if (current == tail) {
                    tail = current.prev;
                    if (tail != null) {
                        tail.next = null;
                    }
                } else {
                    current.prev.next = current.next;
                    current.next.prev = current.prev;
                }
                break;
            }
            current = current.next;
        }
    }

    public void printList() {
        Node current = head;
        while (current != null) {
            System.out.print(current.data + " ");
            current = current.next;
        }
        System.out.println();
    }
}

以上代码中的 `DoublyLinkedList` 类实现了双向链表的常见操作，如在头部和尾部添加节点、删除指定节点以及打印链表。你可以创建 `DoublyLinkedList` 对象并调用相应的方法来操作双向链表。