In practice, you want some arbitrary precision arithmetic (a.k.a. bigint or bignum) library. My recommendation is GMPlib but there are other ones. Don’t try to code your own bignum library. Efficient & clever algorithms exist, but they are unintuitive and difficult to grasp (you can find entire books devoted to that question). In addition, existing … Read more
Consider System.Numerics.BigInteger.
You can use the NSDecimalNumber class from Cocoa. It is not infinite precision, but it can represent 38 decimal digits of precision, which may be enough for what you need.
As of .NET 4.0 you can use the System.Numerics.BigInteger class. See documentation here: http://msdn.microsoft.com/en-us/library/system.numerics.biginteger(v=vs.110).aspx Another alternative is the IntX class. IntX is an arbitrary precision integers library written in pure C# 2.0 with fast – O(N * log N) – multiplication/division algorithms implementation. It provides all the basic operations on integers like addition, multiplication, comparing, … Read more
A fun challenge. 🙂 I assume that you want integers of arbitrary length. I suggest the following approach: Consider the binary nature of the datatype “int”. Think about using simple binary operations to emulate what the circuits in your CPU do when they add things. In case you are interested more in-depth, consider reading this … Read more
Python supports a “bignum” integer type which can work with arbitrarily large numbers. In Python 2.5+, this type is called long and is separate from the int type, but the interpreter will automatically use whichever is more appropriate. In Python 3.0+, the int type has been dropped completely. That’s just an implementation detail, though — … Read more