public static Pow[] GetNarrowPowers(this Rational r, Rational[] narrows = null)
{
if (narrows == null)
{
narrows = NarrowUtils.GetDefault(r.GetInvolvedPowerCount());
}
int len = r.GetInvolvedPowerCount();
if (len > narrows.Length)
{
return(null);
}
Pow[] res = new Pow[len];
r = r.Clone();
for (int i = len - 1; i >= 0; --i)
{
Pow e = r.GetPrimePower(i);
res[i] = e;
if (e != 0)
{
r /= narrows[i].Power(e);
}
}
return(res);
}
