BestBank

You have been hired by BestBank to develop a simple yet secure banking system using procedural programming in C$++.$ BestBank needs a system that allows users to perform essential banking operations through a text$-$based interface. The system should maintain a record of each user's information securely and ensure data integrity at all times.

Requirements of the System:

Create Account: The system should allow new users to create an account by providing a username and password. Usernames must be unique to ensure no two users have the same username. Each new account should start with a balance of zero. The system should provide feedback to the user upon successful account creation or if the username already exists.

Log In: Users should be able to log into their accounts by providing their username and password. The system must verify the credentials and allow access only if the information is correct. If the login attempt is unsuccessful, the system should inform the user and allow them to try again.

Check Balance: Once logged in$,$ users should be able to check their current account balance. This feature should only be accessible to authenticated users.

Deposit Funds: Users should be able to deposit money into their account. The system must validate the deposit amount to ensure it is a positive number and then update the user's balance accordingly. The system should provide feedback to the user upon successful deposit.

Withdraw Funds: Users should be able to withdraw money from their account. The system must check if the user has sufficient funds before allowing the withdrawal. If the user has enough funds, the system should update the balance and provide feedback upon successful withdrawal. If not, the system should inform the user of insufficient funds.

Log Out: Users should be able to log out from their account, which should return them to the main menu. This feature ensures that the session is securely terminated and the user can safely exit their account.

User Menu: The system should have a main menu that is displayed upon starting the program and after each completed operation. The menu should allow users to navigate between creating an account, logging in$,$ and exiting the program.

Key Considerations:

Ensure the system handles input validation and provides clear error messages for invalid inputs.

Maintain the security of user data by using appropriate data structures.

Implement the system using procedural programming principles, ensuring modularity and code readability.

Provide clear and user$-$friendly feedback for all operations.

$3\mathrm{.}1$ Create the User Text Menu and Main Structure

$(10$ marks$)$

$3\mathrm{.}2$ Implement Create Account Functionality

$(10$ marks$)$

$3\mathrm{.}3$ Implement Log In Functionality

$(10$ marks$)$

$3\mathrm{.}4$ Implement Check Balance Functionality

$(5$ marks$)$

$3\mathrm{.}5$ Implement Deposit Funds Functionality

$(5$ marks$)$

$3\mathrm{.}6$ Implement Withdraw Funds Functionality

$(5$ marks$)$

$3\mathrm{.}7$ Implement Log Out Functionality

$(5$ marks$)$