Most efficient implementation of a large number class

When doing calculations on very large numbers where integral data types such as double or int64 falls short, a separate class to handle such large numbers may be needed.

Does anyone care to offer an efficient algorithm on how best to do this?

Solution 1:

There are 2 solutions to your problem:

• Easy way: Use an external library such as 'The GNU MP Bignum Library and forget about implementation details.

• Hard way: Design your own class/structure containing multiple higher order datatypes like double or int64 variables and define basic math operations for them using operator overloading (in C++) or via methods named add, subtract, multiply, shift, etc. (in JAVA and other OO languages).

Let me know if you need any further help. I have done this a couple of times in the past.

Solution 2:

In C# 4.0 use the BigInteger type

Solution 3:

You're asking about arbitrary-precision arithmetic, a subject on which books have been written. If you just want a simple and fairly efficient BigNum library for C#, you might want to check out IntX.