JavaScript uses floating point internally. What is JavaScript’s highest integer value that a number can go to without losing precision? In other words you can’t use more than 53 bits. In some implementations you may be limited to 31. Try storing the bits in more than one variable, use a string, or get a bignum … Read more
GMP is the popular choice. Squeak Smalltalk has a very nice library, but it’s written in Smalltalk. You asked for relevant books or articles. The tricky part of bignums is long division. I recommend Per Brinch Hansen’s paper Multiple-Length Division Revisited: A Tour of the Minefield.
BigInteger is immutable. The javadocs states that add() “[r]eturns a BigInteger whose value is (this + val).” Therefore, you can’t change sum, you need to reassign the result of the add method to sum variable. sum = sum.add(BigInteger.valueOf(i));
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.
The number is held in an int[] – the maximum size of an array is Integer.MAX_VALUE. So the maximum BigInteger probably is (2 ^ 32) ^ Integer.MAX_VALUE. Admittedly, this is implementation dependent, not part of the specification. In Java 8, some information was added to the BigInteger javadoc, giving a minimum supported range and the … Read more
The GNU Multiple Precision Arithmetic Library does what you want http://gmplib.org/ Gnu MP is a C library but it has a C++ class Interface and if you are interested only in big integers, you may just deal with mpz_class. Look at the sample below which I took from the page C++ Interface General int main … Read more
I think a programmer should have implemented his own bignum-library once, so welcome here. (Of course, later you’ll get that BigInteger is better, and use this, but it is a valuable learning experience.) (You can follow the source code of this course life on github. Also, I remade this (a bit polished) into a 14-part … Read more
Use a loop: BigInteger randomNumber; do { randomNumber = new BigInteger(upperLimit.bitLength(), randomSource); } while (randomNumber.compareTo(upperLimit) >= 0); on average, this will require less than two iterations, and the selection will be uniform. Edit: If your RNG is expensive, you can limit the number of iterations the following way: int nlen = upperLimit.bitLength(); BigInteger nm1 = … Read more
It sounds like you’re looking for a way to enter Arbitrary Precision numbers. here are two libraries you could use: GMP and MAPM
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