递归实现合并两个有序链表成一个链表依然有序

Node * MergeRecursive(Node *head1 , Node *head2)
{
    if ( head1 == NULL )
        return head2 ;
    if ( head2 == NULL)
        return head1 ;
    Node *head = NULL ;
    if ( head1->data < head2->data )
   {
       head = head1 ;
       head->next = MergeRecursive(head1->next,head2);
   }
   else
   {
      head = head2 ;
      head->next = MergeRecursive(head1,head2->next);
   }
   return head ;
}