Answer Happy

HERE IS THE JAVA FILE. NEED TO DO THE //TODO STATEMENTS
PLEASE (equals, removeDuplicatesOf,
and removeAllDuplicates)
public class ArrayBag<E> implements BagInterface<E>
{
private E[] bag;
private int size;
// Initial capacity of bag
private static final int DEFAULT_CAPACITY = 25;
/**
* Creates an empty bag whose initial capacity is 25.
*/
public ArrayBag() {
this(DEFAULT_CAPACITY);
}
/**
* Creates an empty bag having a given initial capacity.
* @param initialCapacity The integer capacity desired.
*/
public ArrayBag(int initialCapacity) {
@SuppressWarnings("unchecked")
E[] tempBag = (E[])new Object[initialCapacity];
bag = tempBag;
size = 0;
}
/**
* Creates this bag containing given entries.
* @param contents An array of objects.
*/
public ArrayBag(E[] contents) {
bag = Arrays.copyOf(contents, contents.length);
size = contents.length;
}
/**
* Adds a new entry to this bag.
* @param newEntry The object to be added as a new entry.
* @return True.
*/
@Override
public boolean add(E newEntry) {
if (isArrayFull()) {
doubleCapacity();
}
bag[size] = newEntry;
size++;
return true;
}
/**
* Retrieves all entries that are in this bag.
* @return A newly allocated array of all the entries in this
bag.
*/
@Override
public E[] toArray() {
@SuppressWarnings("unchecked")
E[] result = (E[])new Object[size]; // Unchecked cast
for (int index = 0; index < size; index++) {
result[index] = bag[index];
}
return result;
}
/**
* Sees whether this bag is empty.
* @return True if this bag is empty, or false if not.
*/
@Override
public boolean isEmpty() {
return size == 0;
}
/**
* Gets the current number of entries in this bag.
* @return The integer number of entries currently in this
bag.
*/
@Override
public int getCurrentSize() {
return size;
}
/**
* Counts the number of times a given entry appears in this
bag.
* @param anEntry The entry to be counted.
* @return The number of times anEntry appears in this bag.
*/
@Override
public int getFrequencyOf(E anEntry) {
int counter = 0;
for (int index = 0; index < size; index++) {
if (anEntry != null && anEntry.equals(bag[index])) {
counter++;
}
}
return counter;
}
/**
* Tests whether this bag contains a given entry.
* @param anEntry The entry to locate.
* @return True if this bag contains anEntry, or false
otherwise.
*/
@Override
public boolean contains(E anEntry) {
return getIndexOf(anEntry) > -1; // or >= 0
}
/**
* Removes all entries from this bag.
*/
@Override
public void clear() {
while (!isEmpty()) {
remove();
}
}
/**
* Removes one unspecified entry from this bag, if possible.
* @return Either the removed entry, if the removal was
successful, or
* null.
*/
@Override
public E remove() {
E result = removeEntry(size - 1);
return result;
}
/**
* Removes one occurrence of a given entry from this bag, if
possible.
* @param anEntry The entry to be removed.
* @return True if the removal was successful, or false if
not.
*/
@Override
public boolean remove(E anEntry) {
int index = getIndexOf(anEntry);
E result = removeEntry(index);
return anEntry != null && anEntry.equals(result);
}
// Locates a given entry within the array bag.
// Returns the index of the entry, if located,
// or -1 otherwise.
private int getIndexOf(E anEntry) {
int where = -1;
boolean found = false;
int index = 0;
while (!found && (index < size)) {
if (anEntry != null && anEntry.equals(bag[index])) {
found = true;
where = index;
}
index++;
}
// Assertion: If where > -1, anEntry is in the array bag, and
it
// equals bag[where]; otherwise, anEntry is not in the
array.
return where;
}
// Removes and returns the entry at a given index within the
array.
// If no such entry exists, returns null.
// Precondition: 0 <= givenIndex < size.
private E removeEntry(int givenIndex) {
E result = null;
if (!isEmpty() && (givenIndex >= 0)) {
// Entry to remove
result = bag[givenIndex];
int lastIndex = size - 1;
// Replace entry to remove with last entry
bag[givenIndex] = bag[lastIndex];
// Remove reference to last entry
bag[lastIndex] = null;
size--;
}
return result;
}
// Returns true if the array bag is full, or false if not.
private boolean isArrayFull() {
return size >= bag.length;
}
// Doubles the size of the array bag.
private void doubleCapacity() {
int newLength = 2 * bag.length;
bag = Arrays.copyOf(bag, newLength);
}
/**
* Override the toString() method so that we get a more useful
display of
* the contents in the bag.
* @return a string representation of the contents of the bag
*/
@Override
public String toString() {
StringBuilder result = new StringBuilder("Bag[ ");
for (int index = 0; index < size; index++) {
result.append(bag[index].toString());
result.append(' ');
}
result.append(']');
return result.toString();
}
/**
* Determines if two bags are equal.
* @param other Another object to check this bag against.
* @return True if other is an ArrayBag containing the same
objects, with
* the same frequencies, as this bag.
*/
@Override
public boolean equals(Object other) {
//TODO
return false;
}
/**
* Removes all duplicates of a specific entry from this bag,
leaving only
* one instance of it.
* @param anEntry the entry whose duplicates should be
removed
*/
@Override
public void removeDuplicatesOf(E anEntry){
//TODO
}
/**
* Removes all duplicate items from this bag, leaving one
instance of each
* entry.
*/
@Override
public void removeAllDuplicates() {
//TODO
}
}