Description
The purpose of this assignment is:
* To review basic Java programming concepts
* To review static methods in Java
* To review the Java API (application programming interface)
* To acquaint you with the development system you choose to use
* To learn the required process for submitting homework in this course
* To begin our study of abstraction-based software design with an
algebraic specification for an abstract data type of immutable sets
You will complete an implementation in Java of the FSet ADT
that is specified below. Collaboration between students is
forbidden on this assignment. You are responsible for keeping your
code hidden from all other students. Turn in your work on this
assignment before 11:59 pm on the due date by following instructions
on the course’s main assignments web page,
http://www.ccs.neu.edu/course/cs3500sp13/Assignments.html
Your file of Java code should begin with a block comment that lists
1. Your name, as you want the instructor to write it.
2. Your email address.
3. Any remarks that you wish to make to the instructor.
Part of your grade will depend on the quality and correctness of your
code, part will depend on the readability of your code (comments and
indentation), and part will depend on how well you follow the procedure
above for submitting your work. Assignments submitted between 12:00 am
and 11:59 pm the day after the due date will receive a 20 percentage point
penalty on the assignment.
——————————————————————————————————-
Your assignment is to write the code for a single file, FSet.java,
that implements the specification below. A test program
(/course/cs3500sp13/Assignments/A1/TestFSet.java) will be provided.
——————————————————————————————————-
Specification of the FSet ADT.
FSet is an immutable abstract data type whose values represent
finite sets with elements of type Integer.
The FSet ADT shall be implemented in Java and will be tested on
CCIS Linux machines with only their standard software.
The code for this implementation shall be in the default package and
shall define a public class named FSet. The operations of the
FSet class shall be provided by the following public methods
of the FSet class:
Signature:
Static methods:
emptySet : -> FSet
include : FSet x Integer -> FSet
add : FSet x Integer -> FSet
size : FSet -> int
isEmpty : FSet -> boolean
contains : FSet x Integer -> boolean
isSubset : FSet x FSet -> boolean
remove : FSet x Integer -> FSet
union : FSet x FSet -> FSet
intersect : FSet x FSet -> FSet
Dynamic methods (for which the receiver is an FSet):
toString : -> String
equals : Object -> boolean
hashCode : -> int
Restrictions:
Null arguments may not be passed to any of the above methods
except for equals(Object).
Algebraic specification:
FSet.add (s, k) = s
if FSet.contains (s, k)
FSet.add (s, k) = FSet.include (s, k)
if ! (FSet.contains (s, k))
FSet.size (FSet.emptySet()) = 0
FSet.size (FSet.include (s0, k0))
= FSet.size (s0)
if FSet.contains (s0, k0)
FSet.size (FSet.include (s0, k0))
= 1 + FSet.size (s0)
if ! (FSet.contains (s0, k0))
FSet.isEmpty (FSet.emptySet()) = true
FSet.isEmpty (FSet.include(s0, k0)) = false
FSet.contains (FSet.emptySet(), k) = false
FSet.contains (FSet.include (s0, k0), k)
= true
if k.equals(k0)
FSet.contains (FSet.include (s0, k0), k)
= FSet.contains (s0, k)
if ! (k.equals(k0))
FSet.isSubset (FSet.emptySet(), s2) = true
FSet.isSubset (FSet.include (s0, k0), s2)
= FSet.isSubset (s0, s2)
if FSet.contains (s2, k0)
FSet.isSubset (FSet.include (s0, k0), s2)
= false
if ! (FSet.contains (s2, k0))
FSet.remove (FSet.emptySet(), k) = FSet.emptySet()
FSet.remove (FSet.include (s0, k0), k)
= FSet.remove (s0, k)
if k.equals(k0)
FSet.remove (FSet.include (s0, k0), k)
= FSet.include (FSet.remove (s0, k), k0)
if ! (k.equals(k0))
FSet.union (FSet.emptySet(), s2) = s2
FSet.union (FSet.include (s0, k0), s2)
= FSet.union (s0, s2)
if FSet.contains (s2, k0)
FSet.union (FSet.include (s0, k0), s2)
= FSet.include (FSet.union (s0, s2), k0)
if ! (FSet.contains (s2, k0))
FSet.intersect (FSet.emptySet(), s2) = FSet.emptySet()
FSet.intersect (FSet.include (s0, k0), s2)
= FSet.include (FSet.intersect (s0, s2), k0)
if FSet.contains (s2, k0)
FSet.intersect (FSet.include (s0, k0), s2)
= FSet.intersect (s0, s2)
if ! (FSet.contains (s2, k0))
s.toString() = “{…(” + FSet.size(s) + ” elements,
contains 2: ” + FSet.contains(s, 2) + “)…}”
Values of the FSet ADT shall also implement the public
dynamic methods equals(Object) and hashCode() such that
If s1 is a value of the FSet ADT, then
s1.equals(null) returns false.
If s1 is a value of the FSet ADT, but x is not, then
s1.equals(x) returns false.
If s1 and s2 are values of the FSet ADT, then
s1.equals(s2) if and only if
for every Integer k
FSet.contains (s1, k) if and only if
FSet.contains (s2, k)
If s1 and s2 are values of the FSet ADT, and
s1.equals(s2)
then s1.hashCode() == s2.hashCode().
