c++ - 如何以二进制形式显示C++ Boost Library的多精度大整数？

Question

我是Boost的新手，并尝试使用其多精度库来增加非常大的输入:

mp::uint1024_t my_1024_bit_int1 = 0b00100101101000100010010...010101;
mp::uint1024_t my_1024_bit_int2 = 0b0010101001000101000010100000001001...01010111; // bigger in practice
mp::uint1024_t my_1024_bit_result = my_1024_bit_int2*my_1024_bit_int1;

我需要能够将结果另存为二进制形式的字符串。我试图访问整数中的“肢体”数:

int limbs = my_1024_bit_result.backend.limbs();

然后遍历每个肢体，并使用bitset函数将每个肢体转换为二进制字符串，但是它不起作用。

我还能怎么实现呢？

Answer 1

如果您实际上是指二进制数字:

template <typename Integer>
std::string to_bin(Integer num) {
    auto sign = num.sign();
    num = abs(num);

    std::string result;
    while (num) {
        result += "01"[int(num % 2)];
        num /= 2;
    }
    result += sign<0? "b0-": "b0";
    std::reverse(begin(result), end(result));
    return result;
}

Note how it supports signed types as well

Live On Coliru

int main() {
    mp::uint1024_t a=0b00100101101000100010010010101;
    mp::uint1024_t b=0b001010100100010100001010000000100101010111; // bigger in practice
    mp::uint1024_t c = a * b;

    std::cout << a << " * " << b << " = " << c << "\n";
    std::cout << "\n" << to_bin(a) << " * " << to_bin(b) << "\n = " << to_bin(c) << "\n";
}

版画

78922901 * 726187641175 = 57312835311878048675

0b100101101000100010010010101 * 0b1010100100010100001010000000000000100101010111
= 0b110001101101100000000110000000111101001010111101001000101110100011

序列化？

如果您的意思是“二进制序列化”，请使用序列化:

Writing boost::multiprecision data type to binary file