I need help to solve this program. I have done quite a few parts of it but I don't know how to complete it

Question

Use the following sub-menu for Book Database options:

Study Smart Book Store
Inventory Database

1. Search Book
2. Add Book
3. Edit Book
4. Delete Book
5. Return to the Main Menu
Enter Your Choice:

The shop owner required you to include a simple book database module (Figure 2.0) in the existing system so that all the transactions can be carried out efficiently. In order to group all the book details efficiently, you are required to use the struct data type to model the book entity. You may use the following information in your book record:
struct Book {
string title;
string ISBN;
string author;
string publisher;
int quantity;
double wholesaleCost;
double retailCost;
//could be other elements e.g. publishing date
};

Answer 1

For the initial implementation, you are required to use an array to keep track all the book records and assuming that the array can store up to 100 book records. Implement the following functions in your book database module:
- searchBook: It should ask the user for the title or ISBN of a book. This is a book that is to be looked up in the inventory database

- addBook: It should able to add new book record into an empty slot in the array. If no empty row is found, it means the array is full. In this case, the function should display a message indicating that no more books may be added to the inventory.

- editBook: It should ask the user for the title of a book. This is a book that is to be modified from the inventory database. The function should search the array for a title that matched the one entered by the user. If no match is found, the function should display a message indicating that the book is not in inventory. If the book is found, the function should display the book information and ask the user to edit the selected columns for modification.

- deleteBook: It should ask the user for the title of a book. This is a book that is to be deleted from the inventory database. The function should search the array for a title that matched the one entered by the user. If no match is found, the function should display a message indicating that the book is not in inventory. If the book is found, the function should display the book information and ask the user if they are sure the book’s data are to be deleted from the inventory.

This is the remaining parts