Lab 3: Collection Class

1
C S 272/463 Introduction to Data Structures
Lab 3: Collection Class
I. Requirements
In this lab, you will design a data structure that can be used to store all employees. One of the approaches is
to use a fixed-length array to store all employees. However, this approach has one disadvantage: when the
array is full, we cannot add more employees. Therefore, based on what we have learned in class, you are
asked to design a data structure EmployeeSet whose space can grow automatically and it can be used to
store employees and support basic operations. For employees, you can use your Employee class definition
in Lab2 and add more methods.
The EmployeeSet data structure should implement the functionality of a collection whose space can grow
automatically. This collection data structure does NOT allow you to store the same employee multiple times.
Two employees are considered the same if they have the same employee nos. i.e., if the collection already
contains one Employee object o1, you cannot add another Employee object o2 whose employee no is the
same as o1's employee no.
The class EmployeeSet should define proper instance variables and implement the following methods.
1. (5 pts) This class should include proper instance variables to keep all the distinct employee objects
and the actual number of employees.
2. (5 pts) A no-argument constructor, which initializes an EmployeeSet instance, sets its capacity to
10, and creates an array to store 10 Employee objects.
public EmployeeSet()
3. (10 pts) A copy constructor, which creates a new EmployeeSet instance and copies the content of
the given object to the new instance.
The precondition is that obj should NOT be null and should be an instance of EmployeeSet.
public EmployeeSet(Object obj)
4. (5 pts) The following method which returns the actual number of elements in this collection.
public int size()
5. (5 pts) The following method which returns the capacity of this collection instance.
public int capacity()
6. (10 pts) A method which adds one given Employee object to the first available space of the
employee array in this EmployeeSet instance. When the collection space is sufficient to hold the
new employee, this employee object can be directly added to the collection. Otherwise, you need to
double the space of the instance array by implementing a method ensureCapacity (defined
below). The precondition is that the employee object a should NOT be null.
public void add(Employee a)
7. (10 pts) A method to remove from the collection the employee with the given employee no eno.
public boolean remove(int eno)
2
8. (10 pts) The following method guarantees the capacity of the collection. If this collection's capacity is
smaller than the input parameter, this method sets the capacity to minimumCapacity and enlarges
the array to hold minimumCapacity objects; Otherwise, this collection is left unchanged. The
precondition is that the input parameter minimumCapacity should be positive.
private void ensureCapacity(int minimumCapacity)
9. (15 pts) A method which check whether the collection contains an employee with the given
employee no eno.
public boolean contains(int eno)
10. (15 pts) main() method to thoroughly test your code.
Design test cases, put them in your main method, run your program through the test cases. One test
case need to read all the employee information from the data file (core_dataset.csv on Canvas)
and add those employees to an employee set. You should not use an array with fixed size to keep
the employee information. You cannot use any Java built-in collections (e.g., ArrayList) either.
public static void main(String[] args)
11. (10 pts) Properly run javadoc command to generate java documents for your class.
II. Note
• Specifications for all your classes and methods:
Please properly explain (1) the functionality of the methods, (2) the parameters, (3) the return
values, (4) the pre-conditions if there is any;
Please use inline comments, meaningful variable names, indentation, formatting, and whitespace
throughout your program to improve its readability.
• You can (but are not required to) design and implement other facilitating methods (E.g., other get
and set methods, toString method) to finish the implementation of the required methods.
III. Submission
Submit through canvas a zipped file containing your (1) java file(s) (not .class files) (2) your screenshot of
running javadoc command, (3) the files generated after you run javadoc command.
IV. Grading Criteria
1. The score allocation is beside the questions.
2. Please make sure that you test your code thoroughly by considering all possible test cases. Your
code may be tested using more test cases.