链接列表并按字母顺序插入字符串

我正在编写一个程序，允许用户插入，删除，搜索和打印书籍。这些书必须按字母顺序打印出来。当我插入书籍时，它可以正常工作，但并不会使它们处于正确的顺序，并且会崩溃。这是我的插入功能的代码。

void BookList::Insert(Book* nBook)
    {
        string name;
        int quant;
        double p;
        cout << "Enter the title of the book." << endl;
        cin.ignore();
        getline(cin, name);
        cout << "Enter the number of quanities of this book." << endl;
        cin >> quant;
        cout << "Enter the price of this book." << endl;
        cin.ignore();
        cin >> p;
        nBook->title = name;
        nBook->quantity = quant;
        nBook->price = p;
        nBook->next = nullptr;
        //cout << "test" << endl;
        //If the current book is lexicographically smallest.
        if (first == nullptr) {
            first = nBook;
            cout << first->title << endl;
        }
        else if (nBook->title <= first->title)
        {
            cout << "new first" << endl;
            nBook->next = first;
            first = nBook;
        }
        else
        {
            cout << first->title << endl;
            //if current book is lexicographically small between two books.
            Book* prevPtr = first;
            while (prevPtr != nullptr)
            {
                cout << "Looking at: " << prevPtr->title << endl;
                if (prevPtr->title > nBook->title)
                {
                    break;
                }
                else
                {
                    prevPtr = prevPtr->next;
                }
            }
            nBook->next = prevPtr->next;
            prevPtr->next = nBook;
        }
    }

P.S。这在C 中谢谢