说明：  多项式计算（单向链表的应用） 设计要求：设计处理n次一元多项式P(x) = a0 + a1x + a2x2 + … + anxn,多项式实际上包含n+1项，由n+1个系数唯一确定。为了节省存储空间，只存储多项式中系数非0 的项。运用链表中的每一个结点存放多项式的一个系数非0项，它包含三个域，分别存放该项的系数、指数以及指向下一项结点的指针，来对其进行相应的处理（某一多项式根据x求值、多个同元多项式处理等等）。
(Polynomial calculations (one-way linked list application) design requirements: designed to handle n I. polynomial P (x) = a0+ a1x+ a2x2+ ...+ anxn, polynomials actually contains n+1 entries, the n+1 coefficients uniquely determined. To save storage space, storing only the coefficients of polynomials in non-0 entry. The use of the list in the store each node of a polynomial coefficient non 0, it contains three domains, namely the coefficient store, index and point to a pointer to the next node to its corresponding processing (x evaluated according to a polynomial, a number of the same polynomial processing, etc.).)