biginteger

How to add two numbers of any length in java?

由 a 夏天 提交于 2019-11-27 04:33:51
问题 How to add two numbers of any length in java? Say for example, in java long size is 64 bit. So the maximum range is -9223372036854775808 to 9223372036854775807. Am i right? So if we want to add a number which is greater than this like below, i got a error " Integer Number too large" long a = 9223372036854775807L; long b = 9223372036854775808L; In C, we can take those numbers as char array, by traversing through the address of each char and use some data structure, we can add two numbers of

Handle arbitrary length integers in C++

由 China☆狼群 提交于 2019-11-27 03:55:07
问题 Can someone tell me of a good C++ library for handling (doing operations etc...) with arbitrarily large numbers (it can be a library that handles arbitrary precision floats too, but handling integers is more important)? Please only refer to libraries that YOU used and tell me how did you managed to set it up and pick it up, maybe with a very minimalistic example or something (basically if the mentioned library lacks good documentation provide some input of your own). For the record I'm using

BigInteger division in C#

由 强颜欢笑 提交于 2019-11-27 02:53:15
问题 I am writing a class which needs accurate division of the BigInteger class in C#. Example: BigInteger x = BigInteger.Parse("1000000000000000000000000000000000000000000000000000000000000000000000000000000000000"); BigInteger y = BigInteger.Parse("2000000000000000000000000000000000000000000000000000000000000000000000000000000000000"); x /= y; Console.WriteLine(x.ToString()); //Output = 0 The problem is that being an Integer, naturally it does not hold decimal values. How can I overcome this to

practical BigNum AVX/SSE possible?

由 房东的猫 提交于 2019-11-27 02:14:41
SSE/AVX registers could be viewed as integer or floating point BigNums. That is, one could neglect that there exist lanes at all. Does there exist an easy way to exploit this point of view and use these registers as BigNums either singly or combined? I ask because from what little I've seen of BigNum libraries, they almost universally store and do arithmetic on arrays, not on SSE/AVX registers. Portability? Example: Say you store the contents of a SSE register as a key in a std::set , you could compare these contents as a BigNum. I think it may be possible to implement BigNum with SIMD

A good and basic implementation of BigInt class in C++ [closed]

由 孤街醉人 提交于 2019-11-27 02:12:05
问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 5 years ago . I'm looking for a good and basic BigInt class in C++, I find a lot of implementation but most of the time, it's complex implementation for crypto library... By basic, I mean BigInt can deal with BigInt, long long and strings with operator overloading. If I had time, I had done myself but I do not have time to

Fastest 128 bit integer library [closed]

由 ╄→尐↘猪︶ㄣ 提交于 2019-11-27 01:53:42
问题 I am working on a CPU-heavy numerical computation app. Without going into many details, it's a computational math research project that involves computing a certain function f(x) for large integer x. Right now everything is implemented in C++ in x64 mode, using native 64-bit ints. That limits me to x<2^64~1.8*10^19. I want to go further, to do that, I need a library that does 128-bit arithmetic. And it has to be very fast. In particular, integer divisions should be fast. Otherwise I'll be

Decimals and commas when entering a number into a Ruby on Rails form

由 扶醉桌前 提交于 2019-11-27 01:26:37
问题 What's the best Ruby/Rails way to allow users to use decimals or commas when entering a number into a form? In other words, I would like the user be able to enter 2,000.99 and not get 2.00 in my database. Is there a best practice for this? -- Update --- Does gsub work with floats or bigintegers? Or does rails automatically cut the number off at the , when entering floats or ints into a form? I tried using self.price.gsub(",", "") but get "undefined method `gsub' for 8:Fixnum" where 8 is

How can I find the Square Root of a Java BigInteger?

由 ↘锁芯ラ 提交于 2019-11-27 00:53:31
Is there a library that will find the square root of a BigInteger? I want it computed offline - only once, and not inside any loop. So even computationally expensive solution is okay. I don't want to find some algorithm and implement. A readily available solution will be perfect. 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))

BigInteger Parse Octal String?

由 不想你离开。 提交于 2019-11-26 23:22:45
问题 In Java, I could do //Parsing Octal String BigInteger b = new BigInteger("16304103460644701340432043410021040424210140423204",8); Then format it as I pleased b.toString(2); //2 for binary b.toString(10); //10 for decimal b.toString(16); //16 for hexadecimal C#'s BigInteger offers the formatting capabilities shown above but I can't seem to find a way to parse BIIIG (greater than 64 bit, unsigned) Octal values. 回答1: This may not be the most efficient solution, but if performance is not a

biginteger on Objective-c

由 放肆的年华 提交于 2019-11-26 22:57:41
Can anyone provide code for a BigInteger implementation in objective-c that provides a PowMod function ? iwat 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" mp_int number1, number2, number3; mp_init(&number1); mp_init(&number2); mp_init(&number3); mp_read_radix(&number1, "0a120edfff558c98a73015d5d67e8990", 16); mp_read_radix(&number2,
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