I'm creating a computer application in which I need to be able to calculate the remainder of large numbers (more then $30$ digits). I was searching the Internet for the fastest way to calculate this, but no luck.
I tried one way:
$\ a \ 'Modulus' \ b$
- $b$ must be smaller than $a$
a / b = x round x upwards = y b - ((y * b) - a) = remainder
If x is a round number, there is no remainder.
Now I have $2$ questions:
- Is my method (always) correct?
- Is there any faster way?
Thanks in advance!
EDIT: This is a homework project and I needed to make my own modulus function. That explains why I cannot use the $\%$. Also I builded in a check in my code whether the number was rounded downwards or upwards. If downwards, I'll add $1$.
I know computers can calculate these things fast, yet I want the most simple straight forward method to calculate this, since the numbers I use can become really big. And eventually dividing a big number costs $0.01$secs.. But if there isn't a really fast method, I just have to be happy with the fastest :).