3 Arrays

**D3158** · June 10th, 2011, 02:42 PM

I need to implement 3 arrays as per description (look below)

Linked list must be implemented as three arrays. An array of type Comparable must be used to store the data. Two arrays of integers must be used to represent the linked structure - one array is for the data in use, the other array is for the free list. The values in these arrays are indexes into the data array.

If someone can please volunteer to give me a head start with this, I would truly appreciate it.

I know this is "Java" forums but I can repay you back by assisting you with Web Designing (CSS, Flash, HTML, etc.).

Thank you

**helloworld922** · June 10th, 2011, 06:33 PM

Perhaps you should provide us with what code you currently have, and a detailed description of what issues you're running into? You'll learn a lot more that way (I'm assuming this is a homework assignment or something similar).

If you really don't know where to start, I would recommend The Java Tutorials by Sun Oracle.

**Norm** · June 10th, 2011, 07:24 PM

An array of type Comparable must be used to store the data

That's an interesting use of the Comparable interface. Have you read the API doc for the Comparable interface?
It's mainly used with the sorting/ordering of lists.

**D3158** · June 13th, 2011, 01:54 PM

public static void main(String [ ] args){
int dataArray[] = {2, 1, 4, 3};
int linksArray[] = {4, 0, -1, 2};
int freeListsArray[] = {5, -1};

freeListsArray = dataArray;
freeListsArray = linksArray;
for(int i = 0; i < linksArray.length; i++)
linksArray[i]++;
for(int i = 0; i < dataArray.length; i++)
dataArray[i]++;

Even though I am making tiny progress, this is obviously something I am struggling with. So please help? Thank you.

**Norm** · June 13th, 2011, 02:00 PM

Can you describe what you need to do next and what problems you are having?
What is the purpose/usage of the three arrays you have defined?
Why do you destroy the original value of freeListsArray by assigning it the value of dataArray and then immediately destroy that by assigning it the value of linksArray?

What design work have you done with a piece of paper and a pencil to figure out how to have a linked list and how to link the nodes in the list.
You must design your program before you code it.

**D3158** · June 13th, 2011, 02:32 PM

I am struggling with converting C language to Java language. Can someone please help me with the syntax?

I need to implement 3 arrays. An array of type Comparable must be used to store the data. Two arrays of integers must be used to represent the linked structure - one array is for the data in use, the other array is for the free list. The values in these arrays are indexes into the data array.

This is what I have in C for the program:

HTML Code:

  data =     [two][one][four][][three][];
  links =    [4][0][-1][][2][];
  freelist = [][][][5][][-1];
 
  
  full(){ //checks whether data/links array are full
  	int full = 1;
  	for(int i = 0; i < freekist.length; i++){
  		if(freelist[i] != NULL)
  			full = 0;
  
  	return full; //1 = full and 0 = not full  
  }
  
  empty(){
    	int empty = 1;
    	for(int i = 0; i < data.length; i++){
    		if(data[i] != NULL)
    			empty = 0;
    
  	return full; //1 = empty and 0 = not empty 
    
  }
  
  
  equals() //not really sure what this function is supposed to do
  
  
  iterator(){ //iterates through arrays and prints out data
  int i = 1; //start of data array
  print data[i]; //print first array
  while(links[i] != -1){
  
     i = links[i];  //assign index to i
     print data[i]; //print data
  
  } //should ouput: one two three four
  
  
  }
  
  
  
  insertItem(Comparable item){ //because no position specified, i will assume to add to first free space
  	if(full())
  		print "error, array is full";
  	else {
		for(int i = 0; i < freekist.length; i++){ //find first free location
			if(freelist[i] != NULL)
				break;
		}
		links[i] = freelist[i]; //put location in links
		data[links[i]] = item;  //put item into data
		temp = links[i];
		links[data[temp]] = -1; //show where end of array is
		
  	}  
  }
  
  
  
  
  
  insertItem(Comparable item, int position){
    	if(full())
    		print "error, array is full";
    	else {
    		if(data[position] == NULL){
  			links[position] = freelist[position]; //put location in links
  			data[links[position]] = item;  //put item into data
  			temp = links[position];
  			links[data[temp]] = -1; //show where end of array is
  		else 
  			print "error, location already in use";
  	} 
  
  
  
  }
  
  

  removeItem(int position){
  
  	if (data[position] == NULL)
  		print "error,position already empty";
 	 else {
 	 	data[position] = NULL; //remove data
 	 	for(int i = 0; i < links.length; i++){
 	 		if(links[i] == position){
 	 			links[i] == NULL; //remove link to data
 	 			break;
 	 		}	
 	 	
 	 	}
 	 	freelist[position] = i; //add to freelist
  
  	}
  
  
  }

Thank you!

**Norm** · June 13th, 2011, 03:21 PM

Please enclose your code in code tags to preserve formatting. Unformatted, left adjusted code is hard to read.
Info here:BB Code List - Java Forums

**D3158** · June 13th, 2011, 03:41 PM

@ Norm. Yes. I couldn't find my original thread. Anyways, I gave it a shot with the arrays. I am having issues with insert item and remove item.

Here is my code:

 
 
public final class SimpleComparableList implements SimpleListADT<java.lang.Comparable> {
    private int size;
    private int currentPosition;
    private int capacity;
    private Object data;
    private final int DEFAULT_CAPACITY = 100; 
    private String[] dataArray;
    private int[] linksArray;
    private int[] freeListArray;
 
    public static void main(String [ ] args){          
    }
 
 
    public SimpleComparableList(){
        this.capacity = DEFAULT_CAPACITY;
        this.currentPosition = 1;
        this.dataArray = new String[capacity];
        this.linksArray = new int[capacity];
        this.freeListArray = new int[capacity];
    }
 
    public SimpleComparableList(int capacity){       
    // Constructs and initializes a list that is empty. Current list size is 
    // zero and current position is set to one.        
        this.capacity = capacity;                 
        this.currentPosition = 1; 
        this.dataArray = new String[capacity];
        this.linksArray = new int[capacity];
        this.freeListArray = new int[capacity];        
    }
 
    @Override
    public boolean empty() {
        //throw new UnsupportedOperationException("Not supported yet.");
        return (this.size == 0);        
    }
 
    @Override
    public boolean full() {
        //throw new UnsupportedOperationException("Not supported yet.");
        return (this.size >= this.capacity);        
    }
 
 
    @Override
    public void insertItem(Comparable item) {
        this.insertItem(item, currentPosition);
    }
 
    @Override
    public void insertItem(Comparable item, int position) {
        //throw new UnsupportedOperationException("Not supported yet.");
        if (!(this.full())){
  		print "error, array is full";
        }else{
		for(int i = 0; i < freeListArray.length; i++){ //find first free location
			if(freeListArray[i] != NULL){
				break;
                        }
		linksArray[i] = freeListArray[i]; //put location in links
		dataArray[links[i]] = item;  //put item into data
		temp = linksArray[i];
		linksArray[dataArray[temp]] = -1; //show where end of array is        
                }
        }
    }
 
 
    @Override
    public void removeItem() {
        //throw new UnsupportedOperationException("Not supported yet.");
        this.removeItem(this.currentPosition);        
    }
 
    @Override
    public void removeItem(int position) {
        //throw new UnsupportedOperationException("Not supported yet.");
 
    }
 
    @Override
    public void removeAll() {
        throw new UnsupportedOperationException("Not supported yet.");
    }
 
    @Override
    public int getCurrentListSize() {
        return this.size;
    }
 
    @Override
    public int getCurrentMaxSize() {
        return this.capacity;
    }
 
    @Override
    public int getCurrentPosition() {
        return this.currentPosition;
    }
 
    @Override
    public String getItem() {
        throw new UnsupportedOperationException("Not supported yet.");
    }
 
    @Override
    public void setCurrentPosition(int position) {
        //throw new UnsupportedOperationException("Not supported yet.");
        if (position > this.size) 
            position = this.size;
        if (position < 1) position = 1;
        currentPosition = position;        
    }
 
    @Override
    public void next() {
     //throw new UnsupportedOperationException("Not supported yet.");
    // Increment only the current position of this list if it is not already the 
    // last position.         
        if (this.currentPosition < this.size){
            currentPosition++;
        }else{
            throw new SimpleListException
                    ("Can't increase current on the list");
        }        
    }
 
    @Override
    public void prev() {
        //throw new UnsupportedOperationException("Not supported yet.");
        if (this.currentPosition > 1){
            this.currentPosition--;
        }else{
            throw new SimpleListException
                    ("Can't decrease current on the list");
        }        
    }
 
    @Override
    public void sortList() {
        throw new UnsupportedOperationException("Not supported yet.");
    }
 
    public void quickSort(int array[], int start, int end){
        int i = start;   // index of left-to-right scan
        int k = end;     // index of right-to-left scan
 
        if (end - start >= 1){                   // check that there are at least two elements to sort
            int pivot = array[start];       // set the pivot as the first element in the partition
            while (k > i){                   // while the scan indices from left and right have not met,
              while (array[i] <= pivot && i <= end && k > i)  // from the left, look for the first
                i++;                                    // element greater than the pivot
                  while (array[k] > pivot && k >= start && k >= i) // from the right, look for the first
                    k--;                                        // element not greater than the pivot
                      if(k > i)                                       // if the left seekindex is still smaller than
                        swap(array, i, k);                      // the right index, swap the corresponding elements
            }
 
            swap(array, start, k);          // after the indices have crossed, swap the last element in
                                            // the left partition with the pivot 
            quickSort(array, start, k - 1); // quicksort the left partition
            quickSort(array, k + 1, end);   // quicksort the right partition
        }
        else{return;}    // if there is only one element in the partition, do not do any sorting
                        // the array is sorted, so exit        
}
 
public void swap(int array[], int index1, int index2) {
// pre: array is full and index1, index2 < array.length
// post: the values at indices 1 and 2 have been swapped
 
	int temp = array[index1];           // store the first value in a temp
	array[index1] = array[index2];      // copy the value of the second into the first
	array[index2] = temp;               // copy the value of the temp into the second
}
 
 
 
}

Please help Norm. Thanks.

**Norm** · June 13th, 2011, 03:45 PM

You left off the import statements needed to compile the code. Either post clean code that compiles or post all of the errors you get when you try to compile the code.

Also the main() method is empty. How do you plan to test the code?

**JavaPF** · June 13th, 2011, 03:51 PM

Thanks Norm, I have merged both threads into this one.

**D3158** · June 13th, 2011, 04:12 PM

package util; is the only import statement I have.

There is a separate class provided to me, so when I run it, it runs the test program and I can check what works/does not work. Example: default constructor, insertitem method, remove method, etc.

OUTPUT: at util.SimpleComparableList.insertItem(SimpleCompara bleList.java:77)

which is: throw new SimpleListException("Full list");

Other than that, I do not see any errors.

**Norm** · June 13th, 2011, 04:15 PM

I get lots of errors. package util; is NOT an import statement!

Where is SimpleListADT defined?

Running: D:\Java\jdk1.6.0_25\bin\javac.exe -Xlint -g -deprecation -classpath D:\JavaDevelopment\;.;..\. SimpleComparableList.java

SimpleComparableList.java:13: cannot find symbol
symbol: class SimpleListADT
public final class SimpleComparableList implements SimpleListADT<java.lang.Comparable> {
^
SimpleComparableList.java:13: interface expected here
public final class SimpleComparableList implements SimpleListADT<java.lang.Comparable> {
^
SimpleComparableList.java:46: method does not override or implement a method from a supertype
@Override
^
SimpleComparableList.java:52: method does not override or implement a method from a supertype
@Override
^
SimpleComparableList.java:59: method does not override or implement a method from a supertype
@Override
^
SimpleComparableList.java:71: cannot find symbol
symbol : variable NULL
location: class SimpleComparableList
if(freeListArray[i] != NULL){
^
SimpleComparableList.java:75: cannot find symbol
symbol : variable links
location: class SimpleComparableList
dataArray[links[i]] = item; //put item into data
^
SimpleComparableList.java:75: incompatible types
found : java.lang.Comparable
required: java.lang.String
dataArray[links[i]] = item; //put item into data
^
SimpleComparableList.java:76: cannot find symbol
symbol : variable temp
location: class SimpleComparableList
temp = linksArray[i];
^
SimpleComparableList.java:77: cannot find symbol
symbol : variable temp
location: class SimpleComparableList
linksArray[dataArray[temp]] = -1; //show where end of array is
^
SimpleComparableList.java:77: incompatible types
found : java.lang.String
required: int
linksArray[dataArray[temp]] = -1; //show where end of array is
^
SimpleComparableList.java:64: method does not override or implement a method from a supertype
@Override
^
SimpleComparableList.java:83: method does not override or implement a method from a supertype
@Override
^
SimpleComparableList.java:89: method does not override or implement a method from a supertype
@Override
^
SimpleComparableList.java:95: method does not override or implement a method from a supertype
@Override
^
SimpleComparableList.java:100: method does not override or implement a method from a supertype
@Override
^
SimpleComparableList.java:105: method does not override or implement a method from a supertype
@Override
^
SimpleComparableList.java:110: method does not override or implement a method from a supertype
@Override
^
SimpleComparableList.java:115: method does not override or implement a method from a supertype
@Override
^
SimpleComparableList.java:120: method does not override or implement a method from a supertype
@Override
^
SimpleComparableList.java:137: cannot find symbol
symbol : class SimpleListException
location: class SimpleComparableList
throw new SimpleListException
^
SimpleComparableList.java:129: method does not override or implement a method from a supertype
@Override
^
SimpleComparableList.java:148: cannot find symbol
symbol : class SimpleListException
location: class SimpleComparableList
throw new SimpleListException
^
SimpleComparableList.java:142: method does not override or implement a method from a supertype
@Override
^
SimpleComparableList.java:153: method does not override or implement a method from a supertype
@Override
^
25 errors

1 error(s)

**D3158** · June 13th, 2011, 04:52 PM

Okay. With all respect, instead of completely nitpicking, can you provide assistance? You recommended I should draw a diagram - with a pencil and paper - i did that. You wanted me to provide some code - i provided that - now you won't provide assistance? Just tell me what's wrong with the code I PROVIDED. I will figure the "25 errors" and the "1 error(s)".

**Norm** · June 13th, 2011, 05:02 PM

I am not going to do any of your design work. I will help you get your design to work. I will not write any code for you.
The FIRST thing you must do is provide me with code that executes or if you're getting compiler errors, then a full list of the text of the errors.
Until then we are wasting time.

Just tell me what's wrong with the code I PROVIDED

I gave you a list of the errors I got. Your last post stated: I do not see any errors.
Fix the errors.
Where is the missing class defined?

Good luck on your project.

**D3158** · June 13th, 2011, 05:21 PM

When I run the program I get the compilation error (as follows).

run:
Exception in thread "AWT-EventQueue-0" util.SimpleListException: Full list
at util.SimpleComparableList.insertItem(SimpleCompara bleList.java:77)
at lab3.COMP139Lab3Driver.checkInsertItem2(COMP139Lab 3Driver.java:900)
at lab3.COMP139Lab3Driver.checkIterator(COMP139Lab3Dr iver.java:1046)
at lab3.COMP139Lab3Driver.jButtonDoTestsActionPerform ed(COMP139Lab3Driver.java:695)
at lab3.COMP139Lab3Driver.access$1600(COMP139Lab3Driv er.java:19)
at lab3.COMP139Lab3Driver$22.actionPerformed(COMP139L ab3Driver.java:497)
at javax.swing.AbstractButton.fireActionPerformed(Abs tractButton.java:1995)
at javax.swing.AbstractButton$Handler.actionPerformed (AbstractButton.java:2318)
at javax.swing.DefaultButtonModel.fireActionPerformed (DefaultButtonModel.java:387)
at javax.swing.DefaultButtonModel.setPressed(DefaultB uttonModel.java:242)
at javax.swing.plaf.basic.BasicButtonListener.mouseRe leased(BasicButtonListener.java:236)
at java.awt.Component.processMouseEvent(Component.jav a:6289)
at javax.swing.JComponent.processMouseEvent(JComponen t.java:3267)
at java.awt.Component.processEvent(Component.java:605 4)
at java.awt.Container.processEvent(Container.java:204 1)
at java.awt.Component.dispatchEventImpl(Component.jav a:4652)
at java.awt.Container.dispatchEventImpl(Container.jav a:2099)
at java.awt.Component.dispatchEvent(Component.java:44 82)
at java.awt.LightweightDispatcher.retargetMouseEvent( Container.java:4577)
at java.awt.LightweightDispatcher.processMouseEvent(C ontainer.java:4238)
at java.awt.LightweightDispatcher.dispatchEvent(Conta iner.java:4168)
at java.awt.Container.dispatchEventImpl(Container.jav a:2085)
at java.awt.Window.dispatchEventImpl(Window.java:2478 )
at java.awt.Component.dispatchEvent(Component.java:44 82)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.j ava:644)
at java.awt.EventQueue.access$000(EventQueue.java:85)
at java.awt.EventQueue$1.run(EventQueue.java:603)
at java.awt.EventQueue$1.run(EventQueue.java:601)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectio nPrivilege(AccessControlContext.java:87)
at java.security.AccessControlContext$1.doIntersectio nPrivilege(AccessControlContext.java:98)
at java.awt.EventQueue$2.run(EventQueue.java:617)
at java.awt.EventQueue$2.run(EventQueue.java:615)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectio nPrivilege(AccessControlContext.java:87)
at java.awt.EventQueue.dispatchEvent(EventQueue.java: 614)
at java.awt.EventDispatchThread.pumpOneEventForFilter s(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForFilter(E ventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEventsForHierarch y(EventDispatchThread.java:174)
at java.awt.EventDispatchThread.pumpEvents(EventDispa tchThread.java:169)
at java.awt.EventDispatchThread.pumpEvents(EventDispa tchThread.java:161)
at java.awt.EventDispatchThread.run(EventDispatchThre ad.java:122)
Exception in thread "AWT-EventQueue-0" util.SimpleListException: Full list
at util.SimpleComparableList.insertItem(SimpleCompara bleList.java:77)
at lab3.COMP139Lab3Driver.checkInsertItem2(COMP139Lab 3Driver.java:900)
at lab3.COMP139Lab3Driver.checkIterator(COMP139Lab3Dr iver.java:1046)
at lab3.COMP139Lab3Driver.jButtonDoTestsActionPerform ed(COMP139Lab3Driver.java:695)
at lab3.COMP139Lab3Driver.access$1600(COMP139Lab3Driv er.java:19)
at lab3.COMP139Lab3Driver$22.actionPerformed(COMP139L ab3Driver.java:497)
at javax.swing.AbstractButton.fireActionPerformed(Abs tractButton.java:1995)
at javax.swing.AbstractButton$Handler.actionPerformed (AbstractButton.java:2318)
at javax.swing.DefaultButtonModel.fireActionPerformed (DefaultButtonModel.java:387)
at javax.swing.DefaultButtonModel.setPressed(DefaultB uttonModel.java:242)
at javax.swing.plaf.basic.BasicButtonListener.mouseRe leased(BasicButtonListener.java:236)
at java.awt.Component.processMouseEvent(Component.jav a:6289)
at javax.swing.JComponent.processMouseEvent(JComponen t.java:3267)
at java.awt.Component.processEvent(Component.java:605 4)
at java.awt.Container.processEvent(Container.java:204 1)
at java.awt.Component.dispatchEventImpl(Component.jav a:4652)
at java.awt.Container.dispatchEventImpl(Container.jav a:2099)
at java.awt.Component.dispatchEvent(Component.java:44 82)
at java.awt.LightweightDispatcher.retargetMouseEvent( Container.java:4577)
at java.awt.LightweightDispatcher.processMouseEvent(C ontainer.java:4238)
at java.awt.LightweightDispatcher.dispatchEvent(Conta iner.java:4168)
at java.awt.Container.dispatchEventImpl(Container.jav a:2085)
at java.awt.Window.dispatchEventImpl(Window.java:2478 )
at java.awt.Component.dispatchEvent(Component.java:44 82)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.j ava:644)
at java.awt.EventQueue.access$000(EventQueue.java:85)
at java.awt.EventQueue$1.run(EventQueue.java:603)
at java.awt.EventQueue$1.run(EventQueue.java:601)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectio nPrivilege(AccessControlContext.java:87)
at java.security.AccessControlContext$1.doIntersectio nPrivilege(AccessControlContext.java:98)
at java.awt.EventQueue$2.run(EventQueue.java:617)
at java.awt.EventQueue$2.run(EventQueue.java:615)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectio nPrivilege(AccessControlContext.java:87)
at java.awt.EventQueue.dispatchEvent(EventQueue.java: 614)
at java.awt.EventDispatchThread.pumpOneEventForFilter s(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForFilter(E ventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEventsForHierarch y(EventDispatchThread.java:174)
at java.awt.EventDispatchThread.pumpEvents(EventDispa tchThread.java:169)
at java.awt.EventDispatchThread.pumpEvents(EventDispa tchThread.java:161)
at java.awt.EventDispatchThread.run(EventDispatchThre ad.java:122)

Now, Norm, if you are still gonna ask me to "correct" the above, I am through with you - BECAUSE - the program actually runs. It's a Test Program. It entails the following information:
Default Constructor OK
Constructor with given max size OK
iterator()
insertItem(Comparable item)
insertItem(Comparable item, int position)
removeItem()
removeItem(int position)

Any one else wanna help me out here?

All I am requesting is what is wrong with my insertItem method. I will deal with other problems that you are thinking of.

**Norm** · June 13th, 2011, 05:30 PM

the compilation error (as follows).

I'm sorry, to me it looks like an execution error.

Without a definition for this class: SimpleListADT
I can NOT compile the code. PERIOD. NO WAY to do any more.

**D3158** · June 13th, 2011, 05:34 PM

We are officially done talking. I do not need any assistance from you - ever.

**Norm** · June 13th, 2011, 05:40 PM

Good luck on the project.
Hopefully you'll tell the next guy that tries to help where the parts are that are needed to compile the code.
And I think there is a lot more about your environment that you are not telling.
This reference to a class says a lot: lab3.COMP139Lab3Driver

**dlorde** · June 13th, 2011, 06:57 PM

@D3158 - What do you think this does in your insertItem method?

if (!(this.full())){
    print "error, array is full";
}

If you want more specific help, please post up some compilable code. Norm has been very patient - we don't get paid here, we just spend some precious time trying to help. The least we expect is that people asking for help post code that compiles. The help you will get is proportional to the effort you make to help us to help you. At the end of the day, it's your problem, not ours.

**D3158** · June 14th, 2011, 01:20 PM

I am sorry I was not being co-operative. I was just frustrated and I want to apologize to Norm specially.

Here is my updated source code that compiles (if people still can help me). It runs.

Here is my SimpleListADT.java:

package util;
 
/**
 * Defines a SimpleListADT.
 */
public interface SimpleListADT<T> {
 
  /**
   * Determines if this list is empty.
   * @return <code>true</code> if the list is currently empty, false otherwise.
   */
  public boolean empty();
 
  /**
   * Determines if this list is full.
   * @return <code>true</code> if the list is currently full, or
   *         <code>false</code> otherwise.
   */
  public boolean full();
 
  /**
   * Inserts an <code>item</code> into the list at the current position. If
   * an element occupies the current position before this call, that element
   * will be the new item's successor after the call. The list's current
   * position does not change. The first element in the list is defined to be
   * at position 1 (one) <em>not</em> at position zero (0). To insert an
   * item after the last element in the list (i.e., insert an item which will
   * become the last one and will not have a successor) you must use the
   * <code>insertItem(T, int)</code> method.
   * @see SimpleListADT insertItem(T, int)
   * @param item the item to be inserted.
   * @throws <code>SimpleListException</code> if the list is full.
   */
  public void insertItem(Comparable item);
 
  /**
   * Inserts an <code>item</code> into the list at a specified
   * <code>position</code>. If the list is empty or the <code>position</code>
   * value is less than 1 (one), the item becomes the first one. If
   * <code>position</code> is greater than the current list size, the item
   * becomes the last one. If an element already occupies the specified
   * position, that element will be the new item's successor after the call.
   * Before returning, the current position is updated to <code>item</code>'s
   * position in the list. The current position will not be greater than the
   * current list size.
   * @see SimpleListADT insertItem(T)
   * @param item the item to be inserted.
   * @param position the position in the list that the new item will occupy
   *        after insertion.
   * @throws <code>SimpleListException</code> if the list is full.
   */
  public void insertItem(Comparable item, int positionOnTheList);
 
  /**
   * The element at the current position is removed from the list. If the
   * removed element had a successor then that successor will be at the
   * current position after the removal. The current position is not changed
   * unless the list becomes empty (in that case the current position is set
   * to one) or the last element in the list is removed (in that case the
   * current position is set to the current number of items in the list, after
   * the removal).
   * @see #removeAll()
   * @see #removeItem(int)
   * @throws <code>SimpleListException</code> if the list is empty or the
   *         current position is not set.
   */
  public void removeItem();
 
  /**
   * The element at the specified <code> position </code> is removed from the
   * list. If the removed element had a successor then that successor will be
   * at the vacated position after the removal.  The current position is not
   * changed unless the current position exceeds the length of the list after
   * the removal (in that case the current position is set to the length of the
   * list or 1 (one) if the list becomes empty.
   * @param position the position of the element to be removed.
   * @see #removeAll()
   * @see #removeItem()
   * @throws <code>SimpleListException</code> if the list is empty or the
   *         current position is not set.
   */
  public void removeItem(int positionOnTheList);
 
  /**
   * The list is made empty.
   * @see #removeItem()
   * @see #removeItem(int position)
   * @throws <code>SimpleListException</code> if the list is empty.
   */
  public void removeAll();
 
  /**
   * Obtain the size of the list.
   * @return the current number of elements in the list.
   */
  public int getCurrentListSize();
 
  /**
   * Obtain the maximum size of the list.
   * @return the maximum number of elements that can be stored in the list.
   */
  public int getCurrentMaxSize();
 
  /**
   * Obtain the current position for the list. The list's position indicator is
   * '1-based' <em>not</em> '0-based'. That is, the first position is numbered
   * 1, the second numbered 2, etc. The last position is 'n' where n is the
   * number of items in this list.
   * @return the current position.
   */
  public int getCurrentPosition();
 
  /**
   * Obtain the element at the current position.
   * @return the element stored at the current position in the list.
   * @throws <code>SimpleListException</code> if the list is empty.
   */
  public T getItem();
 
  /**
   * Sets the current position value for the list.  The position value must be
   * between 1 (one) and the number of elements in the list.  If the provided
   * value is less than one (1), the position value will be set to one (1).  If
   * the provided value is greater than the number of elements in the list, the
   * position value will be set to the number of elements in the list.
   * @param position the value for the list's current position.
   */
  public void setCurrentPosition(int position);
 
  /**
   * Increments the current position value for the list if the current
   * position is not already the last position; otherwise, the current position
   * value is not changed.
   * @throws <code>SimpleListException</code> if there is no next element
   * or if the list is empty.
   */
  public void next();
 
  /**
   * Decrements the current position value for the list if the current
   * position is not already the first position; otherwise, the current
   * position value is not changed.
   * @throws <code>SimpleListException</code> if there is no previous element
   * or if the list is empty.
   */
  public void prev();
 
  /**
   * Sorts the list into ascending order according to the natural ordering of
   * the elements. The natural ordering can be determined by the
   * <code>compareTo()</code> method. Before returning to the caller, the
   * current position will be set at the last (end of list) position.
   */
  public void sortList();
}

Here is the SimpleListException.java

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package util;
 
/**
 *
 * @author D3158
 */
public class SimpleListException extends RuntimeException  {
 
    public SimpleListException(String message){
        super(message);
    }
 
 
}

Here is SimpleComparableList.java

package util;
/* @author D3158 */
public final class SimpleComparableList implements SimpleListADT<java.lang.Comparable> {
    private int size;
    private int currentPosition;
    private int capacity;
    private String[] array;      
    //private Object data;
    //private final int DEFAULT_CAPACITY = 100; 
    //private String[] dataArray;
    //private int[] linksArray;
    //private int[] freeListArray;
 
 
    public static void main(String [ ] args){          
    }
 
 
    public SimpleComparableList(){
        this.capacity = 100;
        this.array = new String[this.capacity];        
        this.currentPosition = 1;
        this.size = 0;        
        //this.dataArray = new String[capacity];
        //this.linksArray = new int[capacity];
        //this.freeListArray = new int[capacity];
    }
 
    public SimpleComparableList(int capacity){       
    // Constructs and initializes a list that is empty. Current list size is 
    // zero and current position is set to one.        
        this.capacity = capacity;                 
        this.currentPosition = 1; 
        //this.dataArray = new String[capacity];
        //this.linksArray = new int[capacity];
        //this.freeListArray = new int[capacti];        
        array = new String[capacity];
        this.size = 0;        
    }
 
    @Override
    public boolean empty() {
        //throw new UnsupportedOperationException("Not supported yet.");
        return (size == 0);
 
    }
 
    @Override
    public boolean full() {
        //throw new UnsupportedOperationException("Not supported yet.");
        return (size >= capacity);        
    }
 
 
    @Override
    public void insertItem(Comparable item) {
        //throw new UnsupportedOperationException("Not supported yet.");
        insertItem(item, currentPosition);        
    }
 
    @Override
    public void insertItem(Comparable item, int positionOnTheList) {
        //throw new UnsupportedOperationException("Not supported yet.");
    	if (full()) throw new SimpleListException("Full list");
    	int target = positionOnTheList-1;
    	if (target > size) target = size;
        for(int i = size ; i>target ; i--) array[i] = array[i-1];
        array[target] = (String) item;
        size++;
        currentPosition = positionOnTheList;                
    }
 
 
    @Override
    public void removeItem() {
        //throw new UnsupportedOperationException("Not supported yet.");
        removeItem(currentPosition);        
    }
 
    @Override
    public void removeItem(int positionOnTheList) {
        //throw new UnsupportedOperationException("Not supported yet.");
        if(empty()) throw new SimpleListException("Empty List");
    	size--;
        for(int i = --positionOnTheList ; i<size ; i++) array[i] = array[i+1];
        if (currentPosition > size) currentPosition = size+1;        
    }
 
    @Override
    public void removeAll() {
        //throw new UnsupportedOperationException("Not supported yet.");
        if(empty()) throw new SimpleListException("Empty List");
        size = 0;
        currentPosition = 1;        
    }
 
    @Override
    public int getCurrentListSize() {
        //throw new UnsupportedOperationException("Not supported yet.");
        return this.size;        
    }
 
    @Override
    public int getCurrentMaxSize() {
        //throw new UnsupportedOperationException("Not supported yet.");
        return this.capacity;
    }
 
    @Override
    public int getCurrentPosition() {
        //throw new UnsupportedOperationException("Not supported yet.");
        return this.currentPosition;        
    }
 
    @Override
    public String getItem() {
        //throw new UnsupportedOperationException("Not supported yet.");
        if (empty()) throw new SimpleListException("Empty List");
        return array[currentPosition-1];        
    }
 
    @Override
    public void setCurrentPosition(int position) {
        //throw new UnsupportedOperationException("Not supported yet.");
        if (position > size) position = size+1;
        else if (position < 1) position = 1;
        currentPosition = position;        
    }
 
    @Override
    public void next() {
        //throw new UnsupportedOperationException("Not supported yet.");
        if (currentPosition > size)
        	throw new SimpleListException ("Can't increase current on the list");	
        currentPosition++;        
    }
 
    @Override
    public void prev() {
        //throw new UnsupportedOperationException("Not supported yet.");
        if (currentPosition < 2)
        	throw new SimpleListException("Can't decrease current on the list");
        this.currentPosition--;        
    }
 
    @Override
    public void sortList() {
 
    }  
}

When I run the program, i don't get a compilation error (which is obviously good) and it runs the GUI interface:

Default Constructor OK
Constructor with given max size OK
iterator()
insertItem(Comparable item)
insertItem(Comparable item, int position)
removeItem()
removeItem(int position)

The unchecked ones are the problematic issues. My curiosity is do I need to "fix" the iterator() first so then others will follow or insertItem?

**Norm** · June 14th, 2011, 02:21 PM

Apologies accepted.
You still need to design/describe what you want your code to do.

Have you looked at the java some of the classes in the src.zip file to get some ideas of how java did it?

**D3158** · June 14th, 2011, 02:31 PM

The bottom line are 2 things:
1) The program should run with no compilation errors - Check. It runs.
2) When the program runs, to run the each individual test in the GUI interface (see attached file)lab3tester.jpg - Work in progress

So, so far I only have the 2 test that work:
Default Constructor
Constructor with given max size

Clear now? I hope so!

**Norm** · June 14th, 2011, 02:41 PM

Ok, got it. What is your next step? Which method are you going to do next?
Remember, we're here to help you get your code to work. We don't write your code. You write it.

**D3158** · June 14th, 2011, 03:04 PM

I am trying to get the iterator to work.

Here is the code for it.

    @Override
    public Iterator<String> iterator() {
        //throw new UnsupportedOperationException("Not supported yet.");
        return new SimpleComparableListIterator();        
    }
 
    private int size() {
        // Returns number of elements currently in this bag.
        return size;
    }
 
 
    private class SimpleComparableListIterator implements Iterator<String> {
            private int current;
            private SimpleComparableListIterator() {
            this.current = 0;        
            }
 
        @Override
        public boolean hasNext() {
            //throw new UnsupportedOperationException("Not supported yet.");
            return this.current < SimpleComparableList.this.size();            
        }
 
        @Override
        public String next() {
            //throw new UnsupportedOperationException("Not supported yet.");
             if (this.current < SimpleComparableList.this.size()) {
                return SimpleComparableList.this.array[this.current++];
             }
            throw new NoSuchElementException("List has no more elements");
        }
 
        @Override
        public void remove() {
            throw new UnsupportedOperationException("Not supported yet.");
        }

But it is not working as showed in the image I posted in my previous post.

**Norm** · June 14th, 2011, 03:08 PM

it is not working

Can you explain in more detail what the problem is. What happens? Does it give an error?

I don't see any image in your previous post.

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