diff --git a/tree/binarytree/heap/ArrayListCompleteBinaryTree.java b/tree/binarytree/heap/ArrayListCompleteBinaryTree.java
new file mode 100644
index 0000000..20429c7
--- /dev/null
+++ b/tree/binarytree/heap/ArrayListCompleteBinaryTree.java
@@ -0,0 +1,151 @@
+package tree.binarytree.heap;
+
+import arraylist.IndexList;
+import exceptions.BoundaryViolationException;
+import exceptions.EmptyTreeException;
+import exceptions.InvalidPositionException;
+import position.Position;
+
+import java.util.Iterator;
+
+/**
+ * Created with xgiovio.macbookair.
+ * User: xgiovio
+ * Date: 28/04/14
+ * Time: 15:15
+ */
+public class ArrayListCompleteBinaryTree<E> implements CompleteBinaryTree<E> {
+
+    IndexList<BTPos<E>> T;
+
+    public E remove() throws EmptyTreeException {
+        if(isEmpty()) throw new EmptyTreeException("L’albero è vuoto");
+        return T.remove(size()).element();
+    }
+
+    public Position<E> add(E e) {
+        int i = size() + 1;
+        BTPos<E> p = new BTPos<E>(e,i);
+        T.add(i, p);
+        return p;
+    }
+
+
+    @Override
+    public int size() {
+        return T.size() -1;
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return (size() == 0);
+    }
+
+
+
+
+
+
+    @Override
+    public Position<E> left(Position<E> v) throws InvalidPositionException, BoundaryViolationException {
+        return null;
+    }
+
+    @Override
+    public Position<E> right(Position<E> v) throws InvalidPositionException, BoundaryViolationException {
+        return null;
+    }
+
+    @Override
+    public boolean hasLeft(Position<E> v) throws InvalidPositionException {
+        return false;
+    }
+
+    @Override
+    public boolean hasRight(Position<E> v) throws InvalidPositionException {
+        return false;
+    }
+
+    @Override
+    public Iterable<Position<E>> positions() {
+        return null;
+    }
+
+    @Override
+    public E replace(Position<E> v, E e) throws InvalidPositionException {
+        return null;
+    }
+
+    @Override
+    public Position<E> root() throws EmptyTreeException {
+        return null;
+    }
+
+    @Override
+    public Position<E> parent(Position<E> v) throws InvalidPositionException, BoundaryViolationException {
+        return null;
+    }
+
+    @Override
+    public Iterable<Position<E>> children(Position<E> v) throws InvalidPositionException {
+        return null;
+    }
+
+    @Override
+    public boolean isInternal(Position<E> v) throws InvalidPositionException {
+        return false;
+    }
+
+    @Override
+    public boolean isExternal(Position<E> v) throws InvalidPositionException {
+        return false;
+    }
+
+    @Override
+    public boolean isRoot(Position<E> v) throws InvalidPositionException {
+        return false;
+    }
+
+    @Override
+    public Iterator<E> iterator() {
+        return null;
+    }
+
+
+
+
+
+
+
+
+
+   // check position
+    protected BTPos<E>checkPosition(Position<E> v) throws InvalidPositionException
+    {
+        if (v == null || !(v instanceof BTPos))
+            throw new InvalidPositionException("La posizione non è valida");
+        return (BTPos<E>) v;
+    }
+
+
+     // internal class
+    protected static class BTPos<E> implements Position<E> {
+        E element; int index;
+
+        public BTPos(E elt, int i) {
+            element = elt;
+            index = i;
+        }
+
+        public E element() { return element; }
+
+        public int index() { return index; }
+
+        public E setElement(E elt) {
+            E temp = element;
+            element = elt;
+            return temp; }
+    }
+
+
+}
diff --git a/tree/binarytree/heap/CompleteBinaryTree.java b/tree/binarytree/heap/CompleteBinaryTree.java
new file mode 100644
index 0000000..c60b125
--- /dev/null
+++ b/tree/binarytree/heap/CompleteBinaryTree.java
@@ -0,0 +1,18 @@
+package tree.binarytree.heap;
+
+import position.Position;
+import tree.binarytree.BinaryTree;
+
+/**
+ * Created with xgiovio.macbookair.
+ * User: xgiovio
+ * Date: 28/04/14
+ * Time: 15:12
+ */
+
+
+public interface CompleteBinaryTree <E> extends BinaryTree<E>
+{
+    public Position<E> add(E elem);
+    public  E remove();
+}