LinkedBagclas

public final class LinkedBag> implements BagInterface { private Node firstNode; private int numberOfEntries; public LinkedBag() { firstNode = null; numberOfEntries = 0; } public boolean add(T newEntry) { // Add to beginning of chain: Node newNode = new Node(newEntry); newNode.next = firstNode; // Make new node reference rest of chain // (firstNode is null if chain is empty) firstNode = newNode; // New node is at beginning of chain numberOfEntries++; return true; } public T remove() { T result = null; if (firstNode != null) { result = firstNode.data; firstNode = firstNode.next; // Remove first node from chain numberOfEntries--; } return result; } public boolean remove(T anEntry) { boolean result = false; Node nodeN = getReferenceTo(anEntry); if (nodeN != null) { nodeN.data = firstNode.data; // Replace located entry with entry in first node firstNode = firstNode.next; // Remove first node numberOfEntries--; result = true; } return result; } public void clear() { while (!isEmpty()) { remove(); } } public int getFrequencyOf(T anEntry) { int frequency = 0; Node currentNode = firstNode; while (currentNode != null) { if (anEntry.equals(currentNode.data)) { frequency++; } currentNode = currentNode.next; } return frequency; } public boolean contains(T anEntry) { boolean found = false; Node currentNode = firstNode; while (!found && (currentNode != null)) { if (anEntry.equals(currentNode.data)) { found = true; } else { currentNode = currentNode.next; } } return found; } public boolean isEmpty() { return numberOfEntries == 0; } public int getCurrentSize() { return numberOfEntries; } public T[] toArray() { // The cast is safe because the new array contains null entries @SuppressWarnings("unchecked") T[] result = (T[]) new Comparable[numberOfEntries]; // Unchecked cast int index = 0; Node currentNode = firstNode; while (currentNode != null ) { result[index] = currentNode.data; index++; currentNode = currentNode.next; } return result; } // Locates a given entry within this bag. // Returns a reference to the node containing the entry, if located, or null // otherwise. private Node getReferenceTo(T anEntry) { boolean found = false; Node currentNode = firstNode; while (!found && (currentNode != null)) { if (anEntry.equals(currentNode.data)) { found = true; } else { currentNode = currentNode.next; } } return currentNode; } public T getMax() { T largestValue = null; if (!isEmpty()) { largestValue = firstNode.data; Node currentNode = firstNode.next; while (currentNode != null) { T currentValue = currentNode.data; if (currentValue.compareTo(largestValue) > 0) largestValue = currentValue; currentNode = currentNode.next; } // end while } // end if return largestValue; } @Override public boolean equals(Object obj) { if (obj instanceof LinkedBag>) { LinkedBag otherBag = (LinkedBag) obj; if (this.numberOfEntries == otherBag.numberOfEntries) { // created a copy of the other bag LinkedBag otherCopy = new LinkedBag(); Node otherCurrent = otherBag.firstNode; while (otherCurrent != null) { otherCopy.add(otherCurrent.data); otherCurrent = otherCurrent.next; } // go through the current bag and compare to the other copy bag // when we find a match, remove it from the other copy bag Node current = firstNode; while (current != null) { T currentData = current.data; // remove fails if (!otherCopy.remove(currentData)) { return false; } current = current.next; } // otherCopy is now empty! // same contents! return true; } else { return false; } } else { return false; } } public int removeAll(T item) { // YOUR CODE HERE return 0; // placeholder code: replace with your own return statement(s) } private class Node { private T data; private Node next; private Node(T dataPortion) { this(dataPortion, null); } private Node(T dataPortion, Node nextNode) { data = dataPortion; next = nextNode; } } }

Question 2 16 pts Write a removeAll method for the LinkedBag class. The method takes a value in as a parameter and removes all occurrences of that value. The method returns a count of how many elements were removed. The method header is: public int removeAll(T element)