util.h

#include "BigInt.hpp"
#include <sstream>
#include <string>

namespace util
{
BigInt hexchar_to_int(char ch)
{
    return (ch >= 'a') ? (ch - 'a' + 10) : (ch - '0');
}

auto pow(BigInt base, BigInt power)
{
    BigInt value = 1;
    for (unsigned int i = 0; i < power; i++)
    {
        value = value * base;
    }
    return value;
}

auto hexstream_to_bigint(std::string str)
{
    BigInt val = 0;
    auto len = str.length();
    for (unsigned int i = 0; i < len; i++)
    {
        val = val + util::hexchar_to_int(str[i]) * util::pow(16, len - 1 - i);
    }
    return val;
}

auto int_to_hexstr(std::string val)
{
    std::stringstream stream;
    stream << std::hex << std::atoi(val.c_str());
    return stream.str();
}

std::pair<BigInt, BigInt> divmod(BigInt dividend, BigInt divisor)
{
    return std::make_pair(dividend / divisor, dividend % divisor);
}
} // namespace util