The book solution provided is incorrect. Can someone help me please?

In this project you are to create a database of books that are stored using a vector.

Keep track of the author, title, and publication date of each book. You program should have a main menu that allows the user to select from the following:

(1) Add a book's author, title, and date; (2) Print an alphabetical list of the books sorted by author; and (3) Quit.

You must use a class to hold the data for each book. This class must hold three string fields: one to hold the author's name, one for the publication date, and another to hold the book's title. Store the entire database of books in a vector in which each vector element is a book class object.

To sort the data, use the generic sort function from the library. Note that this requires you to define the < operator to compare two objects of type Book so that the author field from the two books are compared.