use of a hash table is to implement a set data type. You will implement the methods addElement, find, toString, resize, and the MySetIterator inner class in the class MySet. MySet uses a separate chaining hash table to implement a set of integers. To get started, import the starter file, MySet.java into the hashset package you create in a new Java Project. Please do not change any of the method signatures in either class. Implement the methods described below. You are free to test your code however you prefer. Below is method Signature class: package hashset; import java.util.Iterator; public class MySet { // implements a set using a separate chaining hash table private class Node { private Integer element; private Node next; private Node(Integer e, Node n) { element = e; next = n; } } private Node table[]; //an array of linked list private int tableSize; //current number of lists in the table private int numElements; //number of elements in the set private final int primes[] = {7, 23, 59, 131, 271, 563, 1171, 2083, 4441, 8839, 16319, 32467, 65701, 131413, 263983, 528991}; private int primeIndex; //last prime used private int nextPrime(int p) { //finds the next prime from the list above //used for resizing and the initial size while (primes[primeIndex] <= p) primeIndex++; return primes[primeIndex]; } public MySet(int s) { //s is a hint for the initial size primeIndex = 0; tableSize = nextPrime(s); table = new Node[tableSize]; numElements = 0; } //return the hash function value for k private int hash(Integer k) { return Math.abs(k.hashCode() % tableSize); } //"double" the table size and reinsert the values stored in the //current table. the table size should remain prime private void resize() { } //returns true when e is in the set, otherwise returns false public boolean find(Integer e) { return false; } //if e is not in the set add e to the set otherwise the set does not change //if after adding the new element numElements > 2*tableSize then call resize public void addElement(Integer e) { } //returns a string representation for the set //the string representation of the set is { followed by a comma delimiter list of set //elements followed by a }. The string for the empty set is {} //For example, {1,2,3}. //Note that you SHOULD NOT have any spaces in your String /* * Example: * table[0]: 2 -> 4 * table[1]: 1 -> 3 * * The string representation of this set is {2,4,1,3} */ public String toString() { } public class MySetIterator implements Iterator { //implements an iterator for the set private int currentList; private Node currentNode; //helper method that finds the next non empty bucket private void nextList() { while (currentList < tableSize && table[currentList] == null) { currentList++; } currentNode = (currentList < tableSize) ? table[currentList] : null; } public MySetIterator() { currentList = 0; nextList(); } //returns true if the iteration has more elements. public boolean hasNext() { return currentNode != null; } //Returns the next element in the iteration. public Integer next() { Integer rVal = currentNode.element; if (currentNode.next != null) { //what should the currentNode be? } else { //No more elements in the current bucket //I need to get the next bucket } return rVal; } } public Iterator iterator() { //returns an iterator for the set return new MySetIterator
One use of a hash table is to implement a set data type. You will implement the methods addElement, find, toString, resize, and the MySetIterator inner class in the class MySet. MySet uses a separate chaining hash table to implement a set of integers. To get started, import the starter file, MySet.java into the hashset package you create in a new Java Project. Please do not change any of the method signatures in either class. Implement the methods described below. You are free to test your code however you prefer.
Below is method Signature class:
package hashset;
import java.util.Iterator;
public class MySet {
// implements a set using a separate chaining hash table
private class Node {
private Integer element;
private Node next;
private Node(Integer e, Node n) {
element = e;
next = n;
}
}
private Node table[]; //an array of linked list
private int tableSize; //current number of lists in the table
private int numElements; //number of elements in the set
private final int primes[] = {7, 23, 59, 131, 271, 563, 1171,
2083, 4441, 8839, 16319, 32467,
65701, 131413, 263983, 528991};
private int primeIndex; //last prime used
private int nextPrime(int p) {
//finds the next prime from the list above
//used for resizing and the initial size
while (primes[primeIndex] <= p)
primeIndex++;
return primes[primeIndex];
}
public MySet(int s) {
//s is a hint for the initial size
primeIndex = 0;
tableSize = nextPrime(s);
table = new Node[tableSize];
numElements = 0;
}
//return the hash function value for k
private int hash(Integer k) {
return Math.abs(k.hashCode() % tableSize);
}
//"double" the table size and reinsert the values stored in the
//current table. the table size should remain prime
private void resize() {
}
//returns true when e is in the set, otherwise returns false
public boolean find(Integer e) {
return false;
}
//if e is not in the set add e to the set otherwise the set does not change
//if after adding the new element numElements > 2*tableSize then call resize
public void addElement(Integer e) {
}
//returns a string representation for the set
//the string representation of the set is { followed by a comma delimiter list of set
//elements followed by a }. The string for the empty set is {}
//For example, {1,2,3}.
//Note that you SHOULD NOT have any spaces in your String
/*
* Example:
* table[0]: 2 -> 4
* table[1]: 1 -> 3
*
* The string representation of this set is {2,4,1,3}
*/
public String toString() {
}
public class MySetIterator implements Iterator<Integer> {
//implements an iterator for the set
private int currentList;
private Node currentNode;
//helper method that finds the next non empty bucket
private void nextList() {
while (currentList < tableSize && table[currentList] == null) {
currentList++;
}
currentNode = (currentList < tableSize) ? table[currentList] : null;
}
public MySetIterator() {
currentList = 0;
nextList();
}
//returns true if the iteration has more elements.
public boolean hasNext() {
return currentNode != null;
}
//Returns the next element in the iteration.
public Integer next() {
Integer rVal = currentNode.element;
if (currentNode.next != null) {
//what should the currentNode be?
}
else {
//No more elements in the current bucket
//I need to get the next bucket
}
return rVal;
}
}
public Iterator<Integer> iterator() {
//returns an iterator for the set
return new MySetIterator();
}
}
Trending now
This is a popular solution!
Step by step
Solved in 3 steps with 1 images
