Google Foobar挑战级别2“嘿，我已经做到了”

def answer(n, b):

    k = len(n)    m = n    mini_id = []    while m not in mini_id:        mini_id.append(m)        s = sorted(m)        x_descend = ''.join(s[::-1])        y_ascend = ''.join(s)     if b == 10: int_m = int(x_descend) - int(y_ascend) m = str(int_m)        else: int_m_10 = int(to_base_10(x_descend, b)) - int(to_base_10(y_ascend, b)) m = to_base_n(str(int_m_10), b)        m =  (k - len(m)) * '0' + m    return len(mini_id) - mini_id.index(m)