Exercise 2: Add a method boolean contains (Object obj) that checks whether the LinkedList implementation contains a given object. Implement this method by directly traversing the links, not by using...

Java

Extracted text: Exercise 2: Add a method boolean contains (Object obj) that checks whether the LinkedList implementation contains a given object. Implement this method by directly traversing the links, not by using an iterator. Write a tester class to check your method. Exercise 3: Provide a removeLast method for the ArrayList implementation in Section 15.2 that shrinks the internal array by 50 percent when it is less than 25 percent full. Write a tester class to check your method.