_ Add/edit/delete/view a list of customer.
_ Allow customers to subscribe. If they do, whenever there is a new drawing, they are notified.
_ Add/edit/delete/view a list of Vietlott shops.
_ Draw the jackpot by generating 6 numbers between 0 and 45.
_ Buy until the jackpot is obtained. Print the number of times bought + the details for each buy.
_ Run the buying process 5 times and calculate the average number of times one needs to buy to become a winner.
_ Proper try-catch to handle all errors.
_ Singleton
_ Memento
_ Decorator
_ Observer
Programming 1 course.