Notes

// name: date:
public class DLL_shell
{
public static void main(String args[])
{
DLL list = new DLL();

list.addLast("Apple");
list.addLast("Banana");
list.addLast("Cucumber");
list.add("Dumpling");
list.add("Escargot");
System.out.println(list);
System.out.println("Size: " + list.size());
Object obj = list.remove(3);
System.out.println(list);
System.out.println("Size: " +list.size());
System.out.println("Removed "+ obj);
System.out.print("Add at 3: ");
list.add(3,"Cheese");
System.out.println(list);
System.out.println("Get values at 1 and first: " + list.get(1)+" and " + list.getFirst());
System.out.println("No change: " +list);
System.out.println( list.removeFirst() + " is now removed!");
System.out.println(list);
System.out.print("Add first: ");
list.addFirst("Anchovie");
System.out.println(list);
System.out.println("Size: " + list.size());
}
}

//////////////////////////////////////////////////////////

class DLL //DoubleLinkedList
{
private int size;
private DLNode head = new DLNode(); //dummy node--very useful--simplifies the code

public int size()
{
}
/* appends obj to end of list; increases size;
@return true */
public boolean add(Object obj)
{
}
/* inserts obj at position index. increments size.
*/
public void add(int index, Object obj)
{
}
/* return obj at position index.
*/
public Object get(int index)
{
}
/* replaces obj at position index.
*/
public void set(int index, Object obj)
{
}
/* removes the node from position index. decrements size.
@return the object at position index.
*/
public Object remove(int index)
{
}
/* inserts obj at front of list; increases size;
*/
public void addFirst(Object obj)
{
}
/* appends obj to end of list; increases size;
*/
public void addLast(Object obj)
{
}
public Object getFirst()
{
}
public Object getLast()
{
}
public Object removeFirst()
{
}
public Object removeLast()
{
}
public String toString()
{
}
}

///////////////////////////////////////


class DLNode
{
private Object value;
private DLNode prev;
private DLNode next;
public DLNode(Object arg, DLNode p, DLNode n)
{
value=arg;
prev=p;
next=n;
}
public DLNode()
{
value=null;
next=this;
prev=this;
}
public void setValue(Object arg)
{
value=arg;
}
public void setNext(DLNode arg)
{
next=arg;
}
public void setPrev(DLNode arg)
{
prev=arg;
}
public DLNode getNext()
{
return next;
}
public DLNode getPrev()
{
return prev;
}
public Object getValue()
{
return value;
}
}