diff --git a/cg/cg3600.cpp b/cg/cg3600.cpp
new file mode 100755
index 000000000..e26fa53d9
--- /dev/null
+++ b/cg/cg3600.cpp
@@ -0,0 +1,287 @@
+#include <stdlib.h>
+
+#include <array.h>
+
+#include "cg3.h"
+
+///////////////////////////////////////////////////////////
+// TList
+///////////////////////////////////////////////////////////
+
+class TList : public TContainer
+{           
+  enum { MAX_SKIP = 8192 };
+
+  struct TList_object : public TObject
+  { 
+    TObject* _obj;
+    TList_object* _next;
+    TList_object* _prev;
+  };
+
+  TList_object** _skip;
+  long _items, _current;
+  long _step, _last_skip;
+
+protected:
+  // @cmember Ritorna un puntatore al primo oggetto del contenitore
+  virtual TObject* first_item( );
+  // @cmember Ritorna un puntatore all'ultimo oggetto del contenitore
+  virtual TObject* last_item( );
+  // @cmember Ritorna un puntatore all'oggetto successivo all'oggetto corrente
+  virtual TObject* succ_item( );
+  // @cmember Ritorna un puntatore all'oggetto che precede l'oggetto corrente
+  virtual TObject* pred_item( );
+  // @cmember Ritorna il numero di oggetti nel contenitore
+  virtual long objects( );
+
+protected:
+  TList_object* detach_lstobj(long index);
+  TList_object* lstobjptr(long index);
+  void change_step(long step);
+  
+public:
+  
+  TObject* TList::objptr(long index);
+  
+  void destroy();
+  long insert(TObject* obj, long pos);
+  long add(TObject* obj, long pos = -1);
+  
+  TObject* detach(long pos);
+  bool remove(long pos);
+
+  TList(long expected_size);
+  virtual ~TList();
+};
+
+TList::TList(long expected_size)
+          : _items(0), _current(0)
+{
+  _step = expected_size / MAX_SKIP + 1;
+  _last_skip = 0;
+ 
+  _skip = new TList_object*[MAX_SKIP];
+  _skip[0] = NULL;
+}
+
+TList::~TList()
+{
+  destroy();
+  delete [] _skip;
+} 
+
+long TList::objects( )
+{
+  return _items;
+}
+
+TObject* TList::first_item()
+{
+  return objptr(_current = 0);
+}
+
+TObject* TList::succ_item()
+{
+  return objptr(++_current);
+}
+
+TObject* TList::pred_item()
+{
+  return objptr(_current++);
+}
+
+TObject* TList::last_item()
+{
+  return objptr(_current = _items-1);
+}
+
+void TList::destroy() 
+{
+  TList_object* head = _skip[0];
+  while (head)
+  {
+    TList_object* next = head->_next;
+    if (head->_obj)
+      delete head->_obj;
+    delete head;
+    head = next;
+  }
+  _items = _current = _last_skip = 0;
+  _skip[0] = NULL;
+}
+
+TList::TList_object* TList::lstobjptr(long index) 
+{
+  TList_object* lstobj = NULL;
+  const ldiv_t p = ldiv(index, _step);
+  if (p.quot >= 0 && p.quot < _last_skip)
+  {
+    TList_object* lo = _skip[p.quot];
+    for (long s = p.rem; lo && s > 0; s--)
+      lo = lo->_next;
+
+    lstobj = lo;
+  }
+  return lstobj;
+}
+
+TObject* TList::objptr(long index) 
+{
+  TList_object* lo = lstobjptr(index);
+  return lo ? lo->_obj : NULL;
+}
+
+void TList::change_step(long step)
+{
+  CHECKD(step > 0 && step <= 16384, "Bad list step ", step);
+  _step = step;
+  _last_skip = 0;
+  
+  step = 0;       
+  for (TList_object* lo = _skip[0]; lo; lo = lo->_next, step--)
+  {
+    if (step == 0)
+    {
+      CHECK(_last_skip < MAX_SKIP, "Too many items");
+      _skip[_last_skip++] = lo;
+      step = _step; 
+    }
+  }
+}
+             
+long TList::insert(TObject* obj, long index)
+{
+  if (index < 0)
+    index = 0;
+  else  
+  {
+    if (index > _items) 
+      index = _items;
+  }    
+  const long pred = index-1;
+  
+  TList_object* newobj = new TList_object;
+  newobj->_obj = obj;  
+  
+  if (pred < 0)
+  {               
+    newobj->_prev = NULL;
+    newobj->_next = _skip[0];
+    if (_skip[0])
+      _skip[0]->_prev = newobj;
+  }  
+  else
+  {
+    TList_object* lo = lstobjptr(pred);
+    CHECK(lo, "NULL insertion point");
+    newobj->_next = lo->_next;
+    newobj->_prev = lo;
+    if (lo->_next)
+      lo->_next->_prev = newobj;
+    lo->_next = newobj;
+  }
+  _items++;
+  
+  ldiv_t p = ldiv(index, _step);
+  if (p.rem == 0 && p.quot < MAX_SKIP)    // Cambia il capolista
+    _skip[p.quot] = newobj;
+
+  for (long i = p.quot + 1; i < _last_skip; i++)
+    _skip[i] = _skip[i]->_prev;           // Aggiorna capilista successivi
+  
+  // Siamo andati oltre l'ultimo skip
+  const long s = (_items - 1) / _step + 1; 
+  if (s > _last_skip)
+  {
+    if (s > MAX_SKIP)
+      change_step(_step+1);
+    else
+      _last_skip++;
+  }   
+  
+  return index;
+}
+
+long TList::add(TObject* obj, long index)
+{
+  if (index < 0 || index >= _items) 
+  {
+    index = insert(obj, _items);
+  }  
+  else
+  {
+    TList_object* lo = lstobjptr(index);
+    CHECK(lo, "NULL list object");
+    delete lo->_obj;
+    lo->_obj = obj;
+  }
+  return index;  
+}
+
+TList::TList_object* TList::detach_lstobj(long index)
+{
+  TList_object* lo = lstobjptr(index);
+  if (lo)
+  {
+    if (lo->_prev)
+      lo->_prev->_next = lo->_next;
+    if (lo->_next)
+      lo->_next->_prev = lo->_prev;
+    ldiv_t res = ldiv(index, _step);
+    if (res.rem == 0)
+      _skip[res.quot] = lo->_next;
+    long p;
+    for (p = res.quot + 1; p < _last_skip; p++)
+      _skip[p] = _skip[p]->_next;
+      
+    _items--;
+  
+    p = (_items - 1) / _step + 1; 
+    if (p < _last_skip)
+    {                 
+      _last_skip--;
+      _skip[_last_skip] = NULL;
+    }  
+  } 
+  
+  return lo;
+}
+
+TObject* TList::detach(long index)
+{
+  TList_object* lo = detach_lstobj(index);
+  TObject* obj;
+  if (lo)
+  {
+    obj = lo->_obj;
+    delete lo;
+  }  
+  else
+    obj = NULL;
+  return obj;
+}
+
+bool TList::remove(long index)
+{
+  TObject* o = detach(index);
+  if (o)
+    delete o;
+  return o != NULL;
+}   
+
+#include <time.h>
+
+int cg3600(int argc, char* argv[])
+{          
+  long max = 100000L;
+  TList l(max);             
+  const clock_t start = clock();
+  
+  for (long i = 0; i < max; i++)
+    l.add(NULL);
+  
+  const clock_t end = clock()-start;  
+  
+  return 0;
+}
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