两个有序链表合并

递归：
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 ;

}

非递归：
Node* Merge(Node *head, Node *head1, Node *head2){

       Node *tmp=head;

       while(NULL != head1 && NULL != head2)

       {

              if(head1->datadata)

              {

                     tmp->next=head1;

                     tmp=head1;

                     head1=head1->next;

              }

              else

              {

                     tmp->next=head2;

                     tmp=head2;

                     head2=head2->next;

              }

       }

       if(NULL != head1)

       {

              tmp->next=head1;

       }

       if(NULL != head2)

       {

              tmp->next=head2;

       }

       return tmp;

}