Phonebook in c++ without using namespace std

This program is used to create a phonebook for storing contact information into a text file.

The program begins by asking the user to provide a name for the file that will contain their phone book information. It will then ask the user to provide the names and numbers of their contacts. It should keep asking the user for contact information until they type in Done (case-sensitive).

After the user types Done, store all contact information into the file name they provided at the beginning of the program. If the user does not add any contacts, then the file should be empty.

Please see the sample output below to guide the design of your program.

Sample Output:

Please provide the file name for your phone book: contacts.txt Contact 1: Please provide the name: Elsie Simon Please provide their number: (202)555-0115 Contact 2: Please provide the name: Kaisha Cope Please provide their number: 5455689016 Contact 3: Please provide the name: Sultan Vargas Please provide their number: 371-998-4166 Contact 4: Please provide the name: Done Saving phonebook into contacts.txt Done!