Programming Language Concepts
                          Jan-Apr 2009
                          Assignment 2

                  Due Monday, 23 February, 2009

Define a Java class LinearList that can store an arbitrarily long
list of *distinct* integers.  You should implement LinearList as
a linked list in which the nodes of the list are not publicly
visible.

The class should support the following methods:

    public int size();         
    // return the list size
   
    public int indexOf(int elem);
    // return the index of the first occurrence of elem in the list,
    // return -1 if elem is not in the list
   
    public int remove(int index);
    // remove and return the indexth element, elements with higher
    // index have their index reduced by 1
    //
    // if index < 0 or index >= size, remove the first/last
    // element, respectively
   
    public void add(int elem) throws DuplicateValueException;
    // insert elem as the end of the list, if it does not already
    // appear in the list
    //
    // throw DuplicateValueException if the element already occurs
   
    public String toString();
    // output list elements from beginning to end

    public MyIterator getIterator():
    // returns an object that implements the interface
    // MyIterator, given below, pointing to the first value in
    // the list.


public interface MyIterator{

  public abstract boolean hasNext();
    // returns true if the iteration has more elements.

  public abstract int next() throws NoMoreValuesException;
    // returns the next element in the iteration
    //
    // Throw NoMoreValuesException if iteration has no more elements
}


Note: You also have to define the exception classes
      DuplicateValueException and NoMoreValuesException in your code.

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