Where is my System.Numerics namespace?
You need to add an assembly reference to System.Numerics.dll The MSDN entry on BigInteger states: BigInteger Structure … Namespace: System.Numerics Assembly: System.Numerics (in System.Numerics.dll)
biginteger
biginteger on Objective-c
I hope it’s not too late to answer this thread. You can try “LibTomMath” which is opensource and free (the author give away this project as public domain). It works out of the box without any configuration, just put all bn_*.c and tommath*.h to your Xcode project and you are ready to go. #import “tommath.h” … Read more
How do I do big integers in Fortran?
There is no built-in “big number” support, but we can first check whether there is a larger integer kind available (as mentioned by Francescalus above and also many previous pages (e.g. this page). On my computer with gfortran-6.1, the compiler seems to support 128-bit integer kind, so I could calculate the result up to n=160 … Read more
How can I find the Square Root of a Java BigInteger?
Just for fun: public static BigInteger sqrt(BigInteger x) { BigInteger div = BigInteger.ZERO.setBit(x.bitLength()/2); BigInteger div2 = div; // Loop until we hit the same value twice in a row, or wind // up alternating. for(;;) { BigInteger y = div.add(x.divide(div)).shiftRight(1); if (y.equals(div) || y.equals(div2)) return y; div2 = div; div = y; } }
working with incredibly large numbers in .NET
Consider System.Numerics.BigInteger.
Often big numbers become negative
This image shows what you’re looking for. In your case it’s obviously larger numbers, but the principle stays the same. Examples of limits in java are: int: −2,147,483,648 to 2,147,483,647. long: -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807 In the image 0000, 0001 etc, shows the binary representation of the numbers. EDIT: In project euler you often have to … Read more
Bigint (bigbit) library
There are several, including GMP, but for speed, the best is likely TTmath. TTmath’s design decision to use templated fixed lengths at compiletime lets it be quite fast.
Extremely large numbers in javascript
You are going to need a javascript based BigInteger library. There are many to choose from. Here is one https://github.com/peterolson/BigInteger.js You can use it like this var n = bigInt(“91942213363574161572522430563301811072406154908250”) .plus(“91942213363574161572522430563301811072406154908250”);
BigInteger.pow(BigInteger)?
You can write your own, using repeated squaring: BigInteger pow(BigInteger base, BigInteger exponent) { BigInteger result = BigInteger.ONE; while (exponent.signum() > 0) { if (exponent.testBit(0)) result = result.multiply(base); base = base.multiply(base); exponent = exponent.shiftRight(1); } return result; } might not work for negative bases or exponents.
`xrange(2**100)` -> OverflowError: long int too large to convert to int
I believe there is no backport (Py 3’s completely removed the int/long distinction, after all, but in 2.* it’s here to stay;-) but it’s not hard to hack your own, e.g….: import operator def wowrange(start, stop, step=1): if step == 0: raise ValueError(‘step must be != 0’) elif step < 0: proceed = operator.gt else: … Read more