Question 1. Consider the following system,
A group diary and time management system is intended to support the timetabling of meetings and appointments across a group of co-workers.
When an appointment is to be made that involves a number of people, the system finds a common slot in each of their diaries and arranges the appointment for that time. If no common slots are available, it interacts with the user to rearrange his or her personal diary to make room for the appointment.
Determine whether the Publisher-Subscriber design pattern can be applied in this design. Explain your answer clearly. If the answer is yes, identify which classes are suitable for the publisher role and which ones are suitable for the subscriber role. Explain your choices, list the events generated by the Publishers, and state explicitly for each Subscriber to which events it is subscribed to.
Question 2. Consider you are designing the following system,
A filling station (gas station) is to be set up for fully automated operation. Drivers swipe their credit card through a reader connected to the pump; the card is verified by communication with a credit company computer, and a fuel limit is established. The driver may then take the fuel required. When fuel delivery is complete and the pump hose is returned to its holster, the driver's credit card account is debited with the cost of the fuel taken. The credit card is returned after debiting. If the card is invalid, the pump returns it before fuel is dispensed.
Determine what design pattern(s) is/are to be applied in the system. Explain your choice(s) clearly.
Question 3. Explain what is a process? what is a thread? Is multithreading faster than single thread? Give an example to support your answer.
Question 4.Recall a merge sort algorithm sorting an array by recursive calls. Write a program that merge-sort an array by recursively creating threads.
Hint: make MergeSort a thread that create child thread recursively. If you reference code from others work, it must be cited. No copy-paste is allowed.