Challenge question: DsStack copy constructor

Stack::Stack(const Stack& stack) {
   SNode *p = stack.top;
   top = (SNode*)0;

   // get a reversed stack
   while(p) {
    Push(p->data);
    p = p->next;
   }

   // reverse it again
   p = top;
   top = (SNode*)0;
   SNode* del;
   
   while(p) {
    Push(p->data);
    del = p;
    p = p->next;
    delete del;
   }
}