C++中插入双向链表的问题

struct Node {
    int data;
    Node* prev;
    Node* next;
};

class DoublyLinkedList {
private:
    Node* head;
    Node* tail;
public:
    DoublyLinkedList() {
        head = nullptr;
        tail = nullptr;
    }
    // 其他成员函数
};

void DoublyLinkedList::insertNode(int value, int position) {
    Node* newNode = new Node;
    newNode->data = value;
    newNode->prev = nullptr;
    newNode->next = nullptr;

    if (head == nullptr) {
        // 链表为空，插入作为头节点
        head = newNode;
        tail = newNode;
    } else if (position == 0) {
        // 插入作为头节点
        newNode->next = head;
        head->prev = newNode;
        head = newNode;
    } else {
        Node* current = head;
        int count = 0;
        while (current != nullptr && count < position) {
            current = current->next;
            count++;
        }
        if (current == nullptr) {
            // 插入作为尾节点
            tail->next = newNode;
            newNode->prev = tail;
            tail = newNode;
        } else {
            // 插入到当前节点之前
            newNode->prev = current->prev;
            newNode->next = current;
            current->prev->next = newNode;
            current->prev = newNode;
        }
    }
}