(1)．对顺序表的快速排序算法中，如何选取一个界值（又称为轴元素），影响着快速排序的效率，而且界值也并不一定是被顺序表中的一个元素。例如，我们可以用被划分序列中所有元素的平均值作为界值。编写算法实现以平均值为界值的快速排序方法。

(2)．设有n个待排序元素存放在一个不带表头结点的单链表中, 每个链表结点只存放一个元素, 头指针为r。试设计一个算法, 对其进行二路归并排序, 要求不移动结点中的元素, 只改各链结点中的指针, 排序后r仍指示结果链表的第一个结点。

-(1). Fast sorting algorithm order of the table, how to choose a community value (also known as an axis element), affecting the efficiency of quick sort, and community values are not necessarily sequential list is an element. For example, we can be divided by the average of all the elements in the sequence as the cutoff value. Write algorithm is bounded to the average value of fast sorting method.

(2). There n elements to be sorted is stored in a single list without meter nodes, each node lists only a storage element, the head pointer r. Try to design an algorithm, its way merge sort, asked not to move the nodes of elements, each link points only change pointers sorted r still indicates the result list of the first node.