1.  Reverse a singly linked list

// iterative version

                Node* ReverseList( Node ** List )        

{

 Node *temp1 = *List;

 Node * temp2 = NULL;

 Node * temp3 = NULL;

 while ( temp1 )

 {

                                 *List = temp1;                  //set the head to last node             

                               temp2= temp1->pNext; // save the next ptr in temp2

                                  temp1->pNext = temp3; // change next to privous

            temp3 = temp1; 

            temp1 = temp2;

 }

 return *List;

}