C++ How to write this program? [closed]

Need Help

c++ OOP

A parking garage charges a $2.00 minimum fee to park for up to three hours. The garage charges an additional $0.50 per hour for each hour or part thereof in excess of three hours. People who park their cars for longer than 24 hours will pay $8.00 per day. Write a program that calculates and prints the parking charges. The inputs to your program are the date and time when a car enters the parking garage, and the date and time when the same car leaves the parking garage. Keep track of number of cars in the garage overloading ++ and -- operators.

Without using Files and only in C++