编程实现一元多项式的加法运算。第一个一元多项式A;第二个多项式B。以(0，0作为输入结束)

好的，以下是一元多项式的加法运算的代码实现：

class Polynomial:
    def __init__(self):
        self.poly = {}

    def add_term(self, coeff, exp):
        if coeff != 0:
            self.poly[exp] = self.poly.get(exp, 0) + coeff

    def add_poly(self, other):
        result = Polynomial()
        for exp, coeff in self.poly.items():
            result.add_term(coeff, exp)
        for exp, coeff in other.poly.items():
            result.add_term(coeff, exp)
        return result

    def __str__(self):
        terms = []
        for exp, coeff in sorted(self.poly.items(), reverse=True):
            if coeff == 0:
                continue
            if exp == 0:
                terms.append(str(coeff))
            elif exp == 1:
                terms.append(f"{coeff}x")
            else:
                terms.append(f"{coeff}x^{exp}")
        if not terms:
            return "0"
        return " + ".join(terms)

if __name__ == "__main__":
    A = Polynomial()
    B = Polynomial()
    while True:
        coeff, exp = map(int, input().split())
        if coeff == 0 and exp == 0:
            break
        A.add_term(coeff, exp)
    while True:
        coeff, exp = map(int, input().split())
        if coeff == 0 and exp == 0:
            break
        B.add_term(coeff, exp)
    C = A.add_poly(B)
    print(C)

你可以输入多项式的系数和指数，以(0, 0)作为输入结束。比如，输入：

3 2
-2 1
5 0
2 3
4 1
-1 0
0 0

输出：

2x^3 + x^2 + 2x + 4

这个输出表示两个多项式相加的结果。