设计一个一元多项式的简单计算器，其基本功能应有¬ ①输入并建立多项式，②输出多项式，③多项式相加，④多项式相减，⑤多项式的乘积。可利用单链表或单循环链表实现之。-One dollar to design a simple polynomial calculator, and its basic functions ? ① should have input and to establish polynomial, ② output polynomial, ③ polynomial sum, ④ subtract polynomials, ⑤ Polynomials product. Can make use of single-list or the realization of the single round-robin list.