bignum

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? 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

Compiler: MinGW/GCC Issues: No GPL/LGPL code allowed (GMP or any bignum library for that matter, is overkill for this problem, as I already have the class implemented). I have constructed my own 128-bit fixed-size big integer class (intended for use in a game engine but may be generalized to any usage case) and I find the performance of the current multiply and divide operations to be quite abysmal (yes, I have timed them, see below), and I'd like to improve on (or change) the algorithms that do the low-level number crunching. When it comes to the multiply and divide operators, they are

I am still a student, and I find project Euler very fun. sometimes the question requires calculations that are bigger than primitive types. I know you can implement it but I am too lazy to do this, So I tried few libraries, MAPM :: very good performance, but it provides only big floats, with the possibility to check if it is an integer. very good to accept input, but nasty to provide output, and compiles like magic with Visual C++ 2008 express. bigint :: a small one, but needs a re engineering in many parts. Very simple to use, but very limited power, and very slow compared to others. only big

Does .NET come with a class capable of representing extremely large integers, such as 100 factorial? If not, what are some good third party libraries to accomplish this? Jason Olson .NET 4 has a BigInteger class Represents an arbitrarily large signed integer. The BigInteger type is an immutable type that represents an arbitrarily large integer whose value in theory has no upper or lower bounds. This type differs from the other integral types in the .NET Framework, which have a range indicated by their MinValue and MaxValue properties. .NET has a BigInteger class, but it is internal,

In Haskell, what is the difference between an Int and an Integer ? Where is the answer documented? "Integer" is an arbitrary precision type: it will hold any number no matter how big, up to the limit of your machine's memory…. This means you never have arithmetic overflows. On the other hand it also means your arithmetic is relatively slow. Lisp users may recognise the "bignum" type here. "Int" is the more common 32 or 64 bit integer. Implementations vary, although it is guaranteed to be at least 30 bits. Source: The Haskell Wikibook . Also, you may find the Numbers section of A Gentle

I'm working with large numbers that I can't have rounded off. Using Lua's standard math library, there seem to be no convenient way to preserve precision past some internal limit. I also see there are several libraries that can be loaded to work with big numbers: http://oss.digirati.com.br/luabignum/ http://www.tc.umn.edu/~ringx004/mapm-main.html http://lua-users.org/lists/lua-l/2002-02/msg00312.html (might be identical to #2) http://www.gammon.com.au/scripts/doc.php?general=lua_bc (but I can't find any source) Further, there are many libraries in C that could be called from Lua, if the

I would like to add 2 arbitrarily sized integers in C++. How can I go about doing this? Here's an example showing how to use the OpenSSL bignum implementation for arbitrary-precision arithmetic. My example does 2 64 + 2 65 . I'm using Linux. #include <cstdio> #include <openssl/crypto.h> #include <openssl/bn.h> int main(int argc, char *argv[]) { static const char num1[] = "18446744073709551616"; static const char num2[] = "36893488147419103232"; BIGNUM *bn1 = NULL; BIGNUM *bn2 = NULL; BN_CTX *ctx = BN_CTX_new(); BN_dec2bn(&bn1, num1); // convert the string to BIGNUM BN_dec2bn(&bn2, num2); BN