设计一个一元多项式相加的算法程序。

两个一元多项式相加的运算规则是：两个多项式中所有指数相同的项，对应系数相加，若和不为0，则生成“和多项式”中的一项；对于所有指数不为相同的项，则分别复制到“和多项式”中去。

-Design a polynomial sum algorithm. Two unary polynomial sum arithmetic rule is: all indices in the same items of the two polynomials, and added to the corresponding coefficient, and is not 0, it generates a " polynomial"　 All indices are not the same items were copied to the " polynomial" .