PS Group is a company providing utility services to households in Singapore. It supplies cooking gas, electricity, and water. To improve efficiency, the company has decided to introduce a utility billing program* for its customers. The program allows customers to submit their utility meter readings and get the actual bill based on their consumption.

After a discussion with the manager, you received the following information about the desired functions of the system:

1a. Basic Features: Allow customers to login to:

• Submit the meter reading
• Edit and delete the meter reading entered
• Display the bill based on the consumption
• Confirm/save the bill information into the data storage (vector)

1b. Basic Features: Allow staff to login to:

• Set the prices for the utilities
• Set the charges of each service
• Edit and delete the prices of utilities and service charges entered
• Confirm/save the prices of utilities and service charges into the data storage (vector)

2. Integration of above modules 1a and 1b: Allow staff to log in to:

• View the bills of all customers
• View the individual customer bill
• Calculate the total utility bill of all customers

3. Bonus Features

• Allow cost per unit of utility to be uploaded from a text file.
• Add peak and non-peak hours usage and provide a discount on the bill.
• You are not limited to the above features for scoring bonus marks.