[SOLVED] CS2030 Project: Discrete Event Simulator

The simulation starts with three arrival events

The next event to pick is <0.500 1 arrives>. This schedules a SERVE event.

The next event to pick is <0.500 1 served>. This schedules a DONE event.

Finally, statistics of the system that we need to keep track of are:1. the average waiting time for customers who have been served;2. the number of customers served;3. the number of customers who left without being served.In our example, the end-of-simulation statistics are respectively, [0.450 2 1].Priority QueuingThe main structure that is used to manage the events in any discrete event simulation is the Priority Queue. Java provides the PriorityQueue (a mutable class) that can be used to keep a collection of elements, where each element is given a certain priority.Elements may be added to the queue with the add(E e) method. Note that the queue is modified;The poll() method may be used to retrieve and remove the element with the highest priority from the queue. It returns an object of type E, or null if the queue is empty. Note that the queue is modified.Take NoteThe requirements of this project will be released in stages. For each level N, you will be given a driver class MainN in the file MainN.java, and you will be required to create the SimulateN class to go along with it.All utility classes are to be packaged in cs2030.util, while the rest of the classes related to the simulation are to be packaged in cs2030.simulator, with SimulateN as the only public facing classes.The Pair and ImList classes are provided. Compile your code using

and run your program to ensure that everything is still in good working order before proceeding to the next level.Level 0Before delving into the implementation of the simulator, you will need to come up with your own generic immutable priority queue, PQ<T>. Specifically, you will need to construct the following:A constructor that takes in a Comparator and creates an empty PQ<T>A method add that takes in an element of type T and returns the resulting PQA method poll that takes no arguments and removes the highest priority element in the queue (as determined by the Comparator). Note that both the element and the resulting queue should be removed, i.e. the return type should be Pair<T, PQ<T>>A method isEmpty() that returns true if the PQ is empty, or false otherwise A toString method that returns a string representation of the PQAs much as possible, you should adopt the immutable delegation pattern for your implementation. Also note that the Pair class has been provided for you.

n event (i.e. ARRIVE, SERVE, DONE, WAIT, or LEAVE) is associated with a customer and an event time. Events are placed in a priority queue so that they canolled one after another according to the time of occurrence of the event. Let us first create a dummy event EventStub to test that events are processedorrectly using the priority queue, PQ<Event>.the EventStub class, include the constructor that takes in a customer and the event time. Also include an appropriate toString method to return the evenme as a string. ou will also need to define an appropriate EventComparator when creating the priority queue.

evel 2rite an immutable Server class to represent a server that is tagged with a server ID (of type int). The servers provide their services within a shop. As such, rite a Shop class that takes in a list of servers.

execute method takes the current status of the shop, makes changes to the state of the shop based on the event, and returns the next event (if any) andupdated shop status as a pair of values.Now, include the execute method in the EventStub that takes in a Shop, and returns no event (represented by an empty optional) and the same shop as a

Since events are associated with customers and the shop associated with the servers, a particular instance of the simulation can be completely defined by the priority queue of events, as well as the status of the shop. Write the class Simulate2 with a constructor that takes in the number of servers, together with a List<Double> of customer arrival times, and constructs a priority queue of EventStub events using the arrival time as the event time, and the status of the shop.Include a run method within the Simulator2 class that takes no arguments, such that invoking the method will cause the simulation to start by having the events in the priority queue polled one after another until the queue is empty. The run method should return a string.

Use the program Main2.java provided to test your program as shown below. The first input value is the number of servers. This is followed by a sequence of input arrival times associated with each Customer having an identifier 1, 2, 3, respectively. User input is underlined. Input is terminated with a ^D (CTRL-d).Take note of the following assumptions:The format of the input is always correct;Output of a double value, say d, is to be formatted with String.format(%.3f, d);Level 3If you have designed the simulator correctly, this level would only require you to construct the rest of the ARRIVE, SERVE, DONE, WAIT and LEAVE events in order to perform a proper simulation. For each event, you will need to define an appropriate execute method that takes in the current state of the shop, and return the appropriate next event, as well as the updated shop as a pair of values.Using an ARRIVE event at time t as an example, if the execute method takes in a shop with all servers free, then the shop will return a serve event (to be served by 1 at time t), and the shop (no updates are necessary since service has not started). On the other hand, if the event was a SERVE event at time t at then the execute method takes in the shop, and returns a DONE event at time t + 1.0 (assuming service time of 1.0) together with the updated shop with server i tagged as busy.From this point on, you will not be guided with jshell tests. Instead we will only provide sample runs using the provided Main programs.Heres a tip: rather than creating all five events at the same time, you can still develop and test one event at a time. For example, start with the arrival event, and within its execute method, return the EventStub with a later event time. At the same time, you can check the status of the shop to see if the updates are intended. Eventually, all arrival events will be processed and only EventStub events are left in the queue, which are then processed as per the earlier level.Once tested, you can then proceed to let arrive events execute return serve event, and have serve events execute method return EventStub.

he second value of each pair will not read input until the Suppliers get method is invoked. For example,

hat is interesting in the above is that the second customer with the arrival time of 0.6, is the first one to be served with a new input of 1.0. Also note that ifou invoke the same jshell test again, another input is read and returned, rather than returning the value that was last read.

se the program Main5.java provided to test your program. The Lazy class in Lazy.java is also provided; use it if you need to cache the service time of theustomer.ser input starts with an integer value representing the number of servers, and an integer value representing the number of customers. This is followed by the rival times of the customers. Lastly, a number of service times (could be more than necessary) are provided.oreover, rather than typing out the user input, it would be more convenient if you save the input in a file, say test5_1.in and pipe the contents of the file ordirect the file as part of user input.To pipe the contents of the file, use: cat test5_1.in | java Main5To redirect the file, use: java Main5 < test5_1.in