NEED HELP ASAP!!!

public abstract class Container {

// do not change the value of the following constant.

protected final int ORIGINAL_SIZE = 10;

protected Object[] list; // is a container that stores the element of MyList

protected Object[] set; // is a container that stores the element of MySet

protected int size; // this variable holds the actual number of elements that are stored in either of the containers (i.e. MyList or MySet).

/**

* This method adds the obj to the end of the container.

* @param obj is the object that is added to the container.

*/

void add(Object obj) {

System.out.println("The object was added to the contianer");

}

/**

* This method removes the object at the given index

* @param index is the index of the object that is removed.

* @return returns the removed object.

*/

Object remove(int index) {

// Change the return value.

return new Object();

}

/**

* This method returns true if the container is empty.

* @return It returns true if the container is empty, otherwise false.

*/

boolean isEmpty() {

return size == 0 ? true: false;

}

/**

* This method returns the number of elements stored in the container.

* @return It returns the number of elements in the container.

*/

int getSize() {

return size;

}

}

/**

*

* This class simulates an ArrayList, where you can add unlimited number of

* elements to the list.

*

*/

class MyList extends Container{

/**

* This is the default constructor that sets all the instance variables to their defualt value.

*/

public MyList () {

list= new Object[ORIGINAL_SIZE];

size = 0;

}

/**

* This method returns the element that is stored at index index .

* @param index is the index at which the element is accessed and returned.

* @return it returns the element stored at the given index .

*/

public Object get(int index) {

Object obj = list[index];

return obj;

}

/**

* This method overrides the add method defined in class container, by

* adding the obj to the back of list array.

* The original size of the array , is defined by ORIGINAL_SIZE , however, it is possible that

* more elements is added to this array. In case the array does not have enough capacity to add one more element, it grows itself

* by doubling the size of list array.

*/

@Override

void add(Object obj) {

if (size < list.length ) {

list[size] = obj;

}

else {

Object[] arrayCopy = new Object[2*list.length];

int i;

for(i = 0; i < list.length; i++) {

arrayCopy[i] = list[i];

}

arrayCopy[i] = obj;

list = arrayCopy;

}

size++;

}

/**

* This method removes the object at the given index.

* items at index + 1, index + 2, ... should be shifted to index, index + 1, ....

* @pre index is in a valid range.

*/

@Override

Object remove(int index) {

// implement this code. You many need to change the return value

return new Object();

}

/**

* This method returns the elements of the MyList in a form of

* [obj1 obj2 obj3 ...]

*/

@Override

public String toString() {

String result= "[";

for(int i = 0; i

result += list[i] + " ";

result = result.trim() + "]";

return result;

}

}

class MySet extends Container{

public MySet() {

set = new Object[ORIGINAL_SIZE];

size = 0;

}

/**

* This method overrides the add method defined in class container, by

* adding the obj to the back of set array.

* The original size of the set , is defined by ORIGINAL_SIZE , however, it is possible that

* more elements is added to this set. In case the set does not have enough capacity to add one more element, it grows itself

* by doubling the size of set array.

*/

@Override

void add(Object obj) {

// if the array is full, double its size

if (size == set.length ) {

Object[] setCopy = new Object[2*set.length];

for(int i = 0; i

setCopy[i] = set[i];

}

set = setCopy;

}

// check if the obj is already exists

boolean found = false;

for (int i = 0; i < this.getSize(); i++) {

if (set[i].equals(obj)) {

found = true;

break;

}

}

// if the obj does not exists, add it to the set

if (!found) {

set[size] = obj;

size++;

}

}

/**

* This method is an optional method, which means it has not been defiend for this class.

* @param index

* @return

*/

@Override

Object remove(int index) {

// Please do not change this code.

throw new UnsupportedOperationException();

}

/**

* This method returns the elements of the MySet in a form of

* [obj1 obj2 obj3 ...]

*/

@Override

public String toString() {

String result= "[";

for(int i = 0; i

result += set[i] + " ";

result = result.trim() + "]";

return result;

}

}

/**

* This class implements a Stack.

*

*/

class Stack{

private Container stack;

// no other instance variable should be defined here.

/**

* This is the constructor that initializes stack .

*/

public Stack() {

// insert your code here. only one line should be added here.

}

/**

* This method adds the object to the top of the stack.

* @param object is the object that is added to the top of the stack.

*/

public void push(Object object) {

// insert your code here. only one line should be added here.

}

/**

* This method removes an object from the top of the stack.

* @return It returns the object that is returned from the top of the stack.

*/

public Object pop() {

// insert your code here. only one line should be added here. You may need to change the return value.

return new Object();

}

/**

* This method returns the object, which is at the top of the stack without removing it from the stack.

* @return It returns the element, which is found on top of the stack.

*/

public Object top() {

// insert your code here. only one line should be added here. You may want to change the return value.

return new Object();

}

/**

* This method shows how many elements are in the stack.

* @return It returns the number of elements in the stack.

*/

public int getSize() {

// change the return value. No any other code should be added.

return 0;

}

}