实现一个多项式的类（a+b*x+c*x^2+d*x^3+...+），要求输入该多项式的系数和x的值后打印出这个多项式的值。-Achieve a polynomial class (a+ b* x+ c* x ^ 2+ d* x ^ 3+...+), asked to enter the coefficients of the polynomial and the value of x after the number of print type of value.