Level 1

Represent a Cruise

Design an immutable Cruise class to represent a cruise having a unique identifier string, the time of arrival as an integer, the number of loaders required to load the cruise as an integer, and the service time in minutes as an integer.

class Cruise {    private final String identifier;    private final int arrivalTime;    private final int numOfLoader;    private final int serviceTime;    ...}

Note that the time of arrival is in HHMM format. Specifically, 0 or 0000 refers to 00:00 (12AM), 30 or 0030 refers to 00:30 (12:30AM), and 130 or 0130 refers to 01:30 (1:30AM).Implement a getServiceCompletionTime method, which returns the time the service completes (in number of minutes) since midnight, and a getArrivalTime method, which returns the arrival time (in number of minutes) since midnight.For example, if the cruise arrives at 12PM (noon time), the arrival time is (12 * 60) = 720; the service completion time is 12:30PM, which is 750 minutes since midnight, i.e. (12 * 60) + 30 = 750.In addition, implement a getNumOfLoadersRequired method, which returns the number of loaders required to load the cruise.A string representation of a cruise is in the form:

[email protected]

The %0Xd format specifier might be of use to you, where the integer will be represented by an X-digit zero-padded number. For instance,

String.format("%04d", 20);

would return the string 0020.

jshell> /open Cruise.javajshell> new Cruise("A1234", 0, 2, 30)$.. ==> [email protected]jshell> new Cruise("A2345", 30, 2, 30)$.. ==> [email protected]jshell> new Cruise("A3456", 130, 2, 30)$.. ==> [email protected]jshell> new Cruise("A3456", 130, 2, 30).getArrivalTime()$.. ==> 90jshell> new Cruise("A3456", 130, 2, 30).getNumOfLoadersRequired()$.. ==> 2jshell> new Cruise("A3456", 130, 5, 30).getNumOfLoadersRequired()$.. ==> 5jshell> new Cruise("A1234", 0, 2, 30).getServiceCompletionTime()$.. ==> 30jshell> new Cruise("A1234", 0, 2, 45).getServiceCompletionTime()$.. ==> 45jshell> new Cruise("CS2030", 1200, 2, 100).getServiceCompletionTime()$.. ==> 820jshell> new Cruise("D1010", 2329, 2, 30).getServiceCompletionTime()$.. ==> 1439jshell> /exit

Check the format correctness of the output by running the following on the command line:

$ javac *.java$ jshell -q < test1.jsh

Check your styling by issuing the following

$ checkstyle *.java

Level 2

Use Loaders to serve Cruises

Design an immutable Loader class to serve a cruise.

class Loader {    private final int identifier;    private final Cruise cruise;    ...}

Include the following in the Loader class:

• a constructor that takes in an integer denoting its unique identifier, as well as the first cruise that it serves.
• a canServe(Cruise) method that returns true if the loader is available to serve the given cruise, or false otherwise.
• a serve(Cruise) method to serve a given cruise. If the loader is available, the method returns the loader serving this cruise; otherwise the existing loader is returned
• the methods getIdentifier() and getNextAvailableTime() to return the loaders identifier, and the next available time for service.

The string representation of each Loader is in the form:

Loader ID serving [email protected]

jshell> /open Cruise.javajshell> /open Loader.javajshell> new Loader(1, new Cruise("A1234", 0, 1, 30))$.. ==> Loader 1 serving [email protected]jshell> new Loader(1, new Cruise("A1234", 0, 1, 30)).getIdentifier()$.. ==> 1jshell> new Loader(1, new Cruise("A1234", 0, 1, 30)).getNextAvailableTime()$.. ==> 30jshell> new Loader(1, new Cruise("A1234", 0, 1, 30)).canServe(new Cruise("A2345", 30, 1, 30))$.. ==> truejshell> new Loader(1, new Cruise("A1234", 0, 1, 30)).serve(new Cruise("A2345", 30, 1, 30))$.. ==> Loader 1 serving [email protected]jshell> new Loader(1, new Cruise("A1234", 0, 1, 30)).serve(new Cruise("A2345", 30, 1, 30)).getNextAvailableTime()$.. ==> 60jshell> new Loader(1, new Cruise("A1234", 0, 1, 30)).canServe(new Cruise("A2345", 10, 1, 30))$.. ==> falsejshell> new Loader(1, new Cruise("A1234", 0, 1, 30)).serve(new Cruise("A2345", 10, 1, 30))$.. ==> Loader 1 serving [email protected]jshell> new Loader(1, new Cruise("A1234", 0, 1, 30)).serve(new Cruise("A2345", 10, 1, 30)).getNextAvailableTime()$.. ==> 30jshell> new Loader(1, new Cruise("A1234", 0, 1, 30)).serve(new Cruise("A2345", 10, 1, 30)).getIdentifier()$.. ==> 1jshell> /exit

Check the format correctness of the output by running the following on the command line:

$ javac *.java$ jshell -q < test2.jsh

Check your styling by issuing the following

$ checkstyle *.java

Level 3

Represent Small Cruises

Design the SmallCruise class. The arguments of the constructor are its identifier, and time of arrival. Note that you should not need to change your Loader class if you have implemented it properly.

jshell> /open Loader.javajshell> /open Cruise.javajshell> /open SmallCruise.javajshell> new SmallCruise("S0001", 0).getArrivalTime()$.. ==> 0jshell> new SmallCruise("S0001", 0).getServiceCompletionTime()$.. ==> 30jshell> new SmallCruise("S0001", 0).getNumOfLoadersRequired()$.. ==> 1jshell> (Cruise) new SmallCruise("S0123", 1220)$.. ==> [email protected]jshell> new Loader(1, new SmallCruise("S1245", 2330))$.. ==> Loader 1 serving [email protected]jshell> new Loader(1, new SmallCruise("S1245", 2330)).canServe(new SmallCruise("S2345", 2359))$.. ==> falsejshell> new Loader(1, new SmallCruise("S1245", 2330)).serve(new SmallCruise("S2345", 2359))$.. ==> Loader 1 serving [email protected]jshell> new Loader(1, new SmallCruise("S2030", 0))$.. ==> Loader 1 serving [email protected]jshell> /exit

Check the format correctness of the output by running the following on the command line:

$ javac *.java$ jshell -q < test3.jsh

Check your styling by issuing the following

$ checkstyle *.java

Level 4

Represent Big Cruises

Design the BigCruise class. The arguments of the constructor are its identifier, time of arrival, the length of the cruise, and number of passengers, in that order.

jshell> /open Loader.javajshell> /open Cruise.javajshell> /open SmallCruise.javajshell> /open BigCruise.javajshell> Cruise b = new BigCruise("B0001", 0, 70, 3000)jshell> b.getArrivalTime()$.. ==> 0jshell> b.getServiceCompletionTime()$.. ==> 60jshell> b.getNumOfLoadersRequired()$.. ==> 2jshell> new Loader(1, b).serve(b)$.. ==> Loader 1 serving [email protected]jshell> new Loader(1, b).serve(b).getNextAvailableTime()$.. ==> 60jshell> new Loader(2, b)$.. ==> Loader 2 serving [email protected]jshell> new Loader(3, b)$.. ==> Loader 3 serving [email protected]jshell> new Loader(4, new BigCruise("B2345", 0, 30, 1450)).serve(new SmallCruise("S0000", 29))$.. ==> Loader 4 serving [email protected]jshell> new Loader(5, new BigCruise("B3456", 0, 75, 1510)).serve(new SmallCruise("S0001", 30))$.. ==> Loader 5 serving [email protected]jshell> /exit

Check the format correctness of the output by running the following on the command line:

$ javac *.java$ jshell -q < test4.jsh

Check your styling by issuing the following

$ checkstyle *.java

Level 5

Output the loader allocation schedule

Write a method serveCruises(Cruise[]) that takes in an array of cruises, and outputs the allocation schedule of the loaders required to service all the cruises. Save the method in the file level5.jsh.You may assume that there are at most 30 cruises in one day, and the number of loaders servicing a cruise will not exceed 9.

jshell> /open Cruise.javajshell> /open SmallCruise.javajshell> /open BigCruise.javajshell> /open Loader.javajshell> /open level5.jshjshell> Cruise[] cruises = {   ...>     new SmallCruise("S1111", 1300)}jshell> serveCruises(cruises);Loader 1 serving [email protected]jshell> Cruise[] cruises = {   ...>     new BigCruise("B1111", 1300, 80, 3000),   ...>     new SmallCruise("S1111", 1359),    ...>     new SmallCruise("S1112", 1400),    ...>     new SmallCruise("S1113", 1429)}jshell> serveCruises(cruises);Loader 1 serving [email protected]Loader 2 serving [email protected]Loader 3 serving [email protected]Loader 1 serving [email protected]Loader 2 serving [email protected]jshell> Cruise[] cruises = {   ...>     new SmallCruise("S1111", 900),    ...>     new BigCruise("B1112", 901, 100, 1),   ...>     new BigCruise("B1113", 902, 20, 4500),   ...>     new SmallCruise("S2030", 1031),    ...>     new BigCruise("B0001", 1100, 30, 1500),   ...>     new SmallCruise("S0001", 1130)}jshell> serveCruises(cruises);Loader 1 serving [email protected]Loader 2 serving [email protected]Loader 3 serving [email protected]Loader 4 serving [email protected]Loader 2 serving [email protected]Loader 1 serving [email protected]Loader 2 serving [email protected]Loader 1 serving [email protected]jshell> /exit

Check the format correctness of the output by running the following on the command line:

$ javac *.java$ jshell -q < test5.jsh

Check your styling by issuing the following

$ checkstyle *.java

Level 6

Recycled Loaders

The objective of this level is to determine whether your current implementation can be easily extended with minimal modification to the clientThe Cruise Centre has just introduced a new eco-friendly policy in an effort to go green. Their policy states that every third loader that is purchased must be made of recycled materials (referred to as recycled loaders). These recycled loaders will go through a 60-minute long maintenance after every service. It is unable to serve any cruise during this period.For example, if a recycled loader serves a SmallCruise that arrives at 12:30PM, then the next time the loader can serve another Cruise is 2PM (30min + 60min after 12:30PM).By modifying level5.jsh, incorporate the above with minimal modifications to the file level6.jsh.

jshell> /open Cruise.javajshell> /open SmallCruise.javajshell> /open BigCruise.javajshell> /open Loader.javajshell> /open RecycledLoader.javajshell> /open level6.jshjshell> Cruise[] cruises = {   ...>     new BigCruise("B1111", 0, 60, 1500),   ...>     new SmallCruise("S1112", 0),    ...>     new BigCruise("B1113", 30, 100, 1500),   ...>     new BigCruise("B1114", 100, 100, 1500),   ...>     new BigCruise("B1115", 130, 100, 1500),   ...>     new BigCruise("B1116", 200, 100, 1500)   ...> }jshell> serveCruises(cruises);Loader 1 serving [email protected]Loader 2 serving [email protected]Recycled Loader 3 serving [email protected]Loader 1 serving [email protected]Loader 2 serving [email protected]Loader 4 serving [email protected]Loader 1 serving [email protected]Loader 2 serving [email protected]Loader 4 serving [email protected]Loader 1 serving [email protected]Loader 2 serving [email protected]Recycled Loader 3 serving [email protected]Loader 1 serving [email protected]Loader 2 serving [email protected]Loader 4 serving [email protected]jshell> /exit

Check your styling by issuing the following

$ checkstyle *.java