单选题库

void deleteNode(DoublyListNode*& head, int value) {
    DoublyListNode* current = head;
    while (current != nullptr && current->val != value) {
        current = current->next;
    }
    if (current != nullptr) {
        if (current->prev != nullptr) {
            ________________________ // 在此处填入代码
        } else {
            head = current->next;
        }
        if (current->next != nullptr) {
            current->next->prev = current->prev;
        }
        delete current;
    }
}

int factorial(int n) {
    if (n == 0 || n == 1) {
        return 1;
    } else {
        ________________________ // 在此处填入代码
    }
}