bn128 curve 学习笔记

bn128 curve root_of_unity与omega计算关系。 程序代码为：

template
typename std::enable_if::value, FieldT>::type
get_root_of_unity(const size_t n)
{
    const size_t logn = log2(n);
    if (n != (1u  FieldT::s) throw std::invalid_argument("libff::get_root_of_unity: expected logn