# Java代写 | Lab 3 – Implementation of Set ADT Using Binary Search

Lab 3 – Implementation of Set ADT Using Binary Search
Trees
Definitions:
• A set is an unordered collection of elements with no repetition. Examples are the
set of real numbers, the set of integer numbers or the set consisting of numbers
1, 2, 30.
• For this lab we will only be considering representing finite sets consisting of elements
which are integers. Examples: {0, 34, 78, 1000}, {4, 5, 890, 65535}, {0, 1, 2, · · · , 65534, 65535},
{} are all valid sets.
• The union of two sets, say A and B, is written as A∪B and is the set which contains
all of the elements in either A or B or both. Example: If A = {3, 8, 14, 15} and
B = {2, 8, 9, 15, 100}, then A ∪ B = {2, 3, 8, 9, 14, 15, 100} (notice that there are no
repeated elements in a set).
• The intersection of two sets A and B is written as A∩B and is the set which contains
the elements that are common to A and B. Examples: If A = {3, 8, 14, 15} and
B = {2, 8, 9, 15, 100}, then A ∩ B = {8, 15}. If A = {17, 20, 38} and B = {200},
then A ∩ B = {}, which is termed the empty set.
• The difference of two sets A and B is written as A − B and is the set which
contains the elements that are in A but not in B. Examples: If A = {3, 8, 12, 9}
and B = {9, 12, 15, 100}, then A − B = {3, 8} and B − A = {15, 100}.
Specifications:
• You must use the Java class TNode given below, to implement the tree nodes.
Classes TNode and BSTSet must be contained in the same package.
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McMaster University
Dept. Electrical and Comp. Engineering COE 2SI4 – Term II (Winter) 2020
public class TNode{
int element;
TNode left;
TNode right;
TNode(int i, TNode l, TNode r)
{ element =i; left = l; right = r; }
}//end class
• Class BSTSet must contain only one private field named root, of type TNode,
which is a reference to the root of the tree. No other fields are allowed. When the
set is empty you should have root==null.
• Class BSTSet must contain at least the following constructors:
– public BSTSet() – initializes the BSTSet object to represent the empty set
(an empty tree).
– public BSTSet(int[] input) – initializes the BSTSet object to represent the
set containing all elements in array input, without repetitions. For example,
if the array is: 5, 7, 4, 5, then the corresponding set is {5, 7, 4}.
• Class BSTSet must contain the following public methods:
1) public boolean isIn(int v): Returns true if integer v is an element of
this BSTSet. It returns false otherwise.
element of this BSTSet. It does nothing otherwise.
3) public boolean remove(int v): Removes v from this BSTSet if v was an
element of this BSTSet and returns true. Returns false if v was not an
element of this BSTSet.
4) public BSTSet union(BSTSet s): Returns a new BSTSet which represents
the union of this BSTSet and s. This method should not modify the input
sets.
5) public BSTSet intersection(BSTSet s): Returns a new BSTSet which represents
the intersection of this BSTSet and s. This method should not modify
the input sets.
6) public BSTSet difference(BSTSet s): Returns a new BSTSet which represents
the difference of this BSTSet and s. This method should not modify
the input sets.
7) public int size(): Returns the number of elements in this set.
8) public int height(): Returns the height of this BSTSet. Height of empty
set is -1.
9) public void printBSTSet(): Outputs the elements of this set to the console,
in increasing order.
private void printBSTSet(TNode t): Outputs to the console the elements
stored in the subtree rooted in t, in increasing order.
For the two printing methods specified above you must use the following code
public void printBSTSet(){
if(root==null)
2 of 4
McMaster University
Dept. Electrical and Comp. Engineering COE 2SI4 – Term II (Winter) 2020
System.out.println(“The set is empty”);
else{
System.out.print(“The set elements are: “);
printBSTSet(root);
System.out.print(“\n”);
}
}
private void printBSTSet(TNode t){
if(t!=null){
printBSTSet(t.left);
System.out.print(” ” + t.element + “, “);
printBSTSet(t.right);
}
}
9) public void printNonRec(): Prints the integers in this BSTSet in increasing
order. This method is nonrecursive and uses a stack to implement the
inorder traversal.
Notes:
• Compute the asymptotic run time and space complexity of all methods implemented
as a function of the set size. Be prepared to present your derivations to
the TA at demo time and provide verbal justification for your analysis.
• You are permitted to implement other private methods inside class BSTSet as
required. However, you are not permitted to modify the class TNode. Additionally,
class BSTSet must contain only one field which is at TNode reference named root.
• You may use the code from the lecture notes on binary search trees, stack and
queues, or from the tutorial. However, you may need to adapt the code and
provide complete references.
• To get credit for the lab you must demonstrate your code (i.e., class BSTSet and
the test class) in front of a TA during your lab session. A 50% penalty will be
applied for either a late demo or if the electronic submission of the code is late. E-mail: [email protected]  微信:itcsdx 