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Exercise 2: Implementing an Array List

Modify the class ArrayList given in Exercise 1 by using expandable arrays. That is, if the list is full when an item is being added to this list, the elements will be moved to a larger array. The new array should have twice the size of the original array.

Exercise 3: Using an Array-Based List

Using the class ArrayList completed in the previous exercise, write a program to store 1,000 random numbers, each in the interval [0, 500]. The initial size of the array in the class should be set to 100. Print the numbers.

Exercise 4: Implementing a Bag Class

Create a class bag (multiset) that uses an expandable array to store the bag items. The item type must be a Java String type; that is, the bag will store strings of characters. The class should have the methods listed below. Create a main class to test your bag class and demonstrate each of these methods. This main class should fill a bag with the keywords of the Java language.

Bag(): default constructor

boolean isEmpty(): determines whether the bag is empty (still need it)

void print(): prints the bag elements (still need it)

int getLength(): returns the number of items in the bag (still need it for expansion)

void add(String item): adds an item to the bag

void removeOne(String item): removes item from the bag; only one occurrence of item should be removed.

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