Implementato interamente un tda sequenze usando array (ArrayIndexList). Aggiunto reverse di sequenze in global.

sequence/utility/DNodeIndex.java

@@ -13,35 +13,27 @@ import position.Position;
 //Additional modifications and methods by xgiovio
 
 public class DNodeIndex<E> implements Position<E> {
-  private DNodeIndex<E> prev = null;
-  private DNodeIndex<E> next = null;
   private E element = null;
   private int index = -1;
 
 
-  public DNodeIndex(DNodeIndex<E> newPrev, DNodeIndex<E> newNext, E elem, int in_idex) {
-    prev = newPrev;
-    next = newNext;
+  public DNodeIndex( E elem, int in_idex) {
+
     element = elem;
     index = in_idex;
   }
-    public DNodeIndex(DNodeIndex<E> newPrev, DNodeIndex<E> newNext, E elem) {
-        prev = newPrev;
-        next = newNext;
+  public DNodeIndex( E elem) {
+
         element = elem;
-    }
+  }
 
   public E element() throws InvalidPositionException {
-    if ((prev == null) && (next == null))
+    if (index == -1)
       throw new InvalidPositionException("Position is not in a list!");
     return element;
   }
 
-  public DNodeIndex<E> getNext() { return next; }
-  public DNodeIndex<E> getPrev() { return prev; }
 
-  public void setNext(DNodeIndex<E> newNext) { next = newNext; }
-  public void setPrev(DNodeIndex<E> newPrev) { prev = newPrev; }
   public void setElement(E newElement) { element = newElement; }
 
     public int getIndex() {