Chapter 7, Problem 14E

Modified class for “OneWayNoRepeatsList.java”

//Define "OneWayNoRepeatsList" class

public class OneWayNoRepeatsList

{

  //Declare required variables

  public static int START_POSITION = 1;

  public static int DEFAULT_SIZE = 50;

//entry.length is the total number of items you have room

//for on the list (its capacity); countOfEntries is the number of 

  //items currently on the list.

private int countOfEntries; //can be less than entry.length.

    private String[] entry;

  /**

    Creates an empty list with a given capacity

    */

    public OneWayNoRepeatsList(int maximumNumberOfEntries)

    {

        //Add "1" to the maximum number of entries

        entry = new String[maximumNumberOfEntries + 1];

        //Assign count of entries to "0"

        countOfEntries = 0;

    }

    /**

    Creates an empty list with a capacity of DEFAULT_SIZE.

    */

    public OneWayNoRepeatsList()

    {

        //Add "1" to "DEFAULT_SIZE"

        entry = new String[DEFAULT_SIZE + 1];

        countOfEntries = 0;

// or replace these two statements with this(DEFAULT_SIZE);

    }

    //Method definition for "isFull"

    public boolean isFull()

    {

/* Returns "true" if the total number of entries equal to one less than the size of entry. Otherwise, returns "false". */

        return countOfEntries == entry.length - 1;

    }

    //Method definition for "isEmpty"

    public boolean isEmpty()

    {

        return countOfEntries == 0;

    }

    /**

    Precondition: List is not full.

    Postcondition: If item was not on the list,

    it has been added to the list.

    */

    public void addItem(String item)

    {

        if (!isOnList(item))

        {

            if (countOfEntries == entry.length - 1)

            {

System.out.println("Attempt to add to a full list!");

                System.exit(0);

            }

            else

            {

/* Here the value of entry start from 1 that is entry[1]. Hence it ignores entry[0] */

                entry[countOfEntries + 1] = item;

                //Increment the count of entries value

                countOfEntries++;

            }

        }

        //else do nothing. Item is already on the list.

    }

    /**

    If the argument indicates a position on the list,

    the entry at that specified position is returned;

    otherwise, null is returned.

    */

    public String getEntryAt(int position)

    {

        String result = null;

        /* Here the index of position start from "1".

If the value of "position" satisfy the given condition, then returns the value at given index. Otherwise returns "null" */

if ((1 <= position) && (position <= countOfEntries))

            result = entry[position];

        return result;

    }

    /**

    Returns true if position indicates the last item

    on the list; otherwise, returns false...