public static BigNum operator *(BigNum a, BigNum b)
{
BigNum ret = new BigNum();
for (int i = 0; i < b._element.Count; i++)
{
if (b.GetElement(i) == 0)
continue;
for (int j = 0; j < a._element.Count; j++)
{
if (a.GetElement(j) == 0)
continue;
ret.SetElement(i + j, ret.GetElement(i + j) + a.GetElement(j) * b.GetElement(i));
}
ret.Refine();
}
ret._isNegtive = a._isNegtive ^ b._isNegtive;
ret._dotPos = a._dotPos + b._dotPos;
return ret;
}
