欧拉计划 16

2 ** 15 = 32768 并且其各位之和为 is 3 + 2 + 7 + 6 + 8 = 26.

2 ** 1000 的各位数之和是多少？

# 按位求取
n = 1000
num = 2
pow_list = [num]
for i in range(n - 1):
    d = 0
    for j in range(len(pow_list)):
        pow_list[j] = d + pow_list[j] * num
        d = pow_list[j] // 10
        pow_list[j] %= 10
    if d > 0:
        pow_list.append(d)
print(sum(pow_list))


# 直接求和
print(sum([int(i) for i in str(2 ** 1000)]))