biginteger

问题 I am currently working with the .NET port of BouncyCastle and I am having some trouble converting a big integer into a System.Guid using the native .NET BigInteger . For some context, I am using BouncyCastle in one ("source") application to convert a System.Guid to a Org.BouncyCastle.Math.BigInteger . This value is then saved as a string in the format 3A2B847A960F0E4A8D49BD62DDB6EB38 . Then, in another ("destination") application, I am taking this saved string value of a BigInteger and am

问题 I'm playing with the El Gamal cryptosystem, and my goal is to be able to encipher and decipher long sequences of text. El Gamal requires the plaintext to be an integer. I have turned my string into a byte[] using the .getBytes() method for Strings, and then created a BigInteger out of the byte[]. After encryption/decryption, I turn the BigInteger into a byte[] using the .toByteArray() method for BigIntegers, and then create a new String object from the byte[]. I am using a 1035 bit key, and

问题 I am trying to do Factorial with Recursion and BigIntegers but eclipse is complaining about the BigInteger. I know the program is supposed to be simple but it is giving me headache. Here is the code. import java.util.Scanner; import java.math.BigInteger; public class Factorial { public static void main(String[] args) { Scanner input = new Scanner(System.in); System.out.println("Enter integer"); BigInteger n = input.nextBigInteger(); System.out.println("Factorial of " + n + " is " + fact(n));

问题 This question already has answers here : Closed 7 years ago . Possible Duplicate: What does BigInteger having no limit mean? The Javadoc for BigInteger does not define any maximum or minimum. However, it does say: (emphasis added) Immutable arbitrary-precision integers Is there such a maximum, even in theory? Or is the way BigInteger operates fundamentally different, such that there is in reality no maximum except for the amount of memory available on the computer? 回答1: The number is held in

问题 I need a 16-byte binary data column to be unique. Why can't a BLOB(16) be unique in MySQL and MariaDB, when it supports unique VARCHAR? That this is supported but not a fixed-length set of bytes seems nuts. Also, it's not acceptable to waste space by storing a binary value in base64 encoded strings. So, any better option than converting to/from two BIGINTs that make a composite unique index (this 16-byte binary is not used as a primary key, if it matters)? (Also, if I do use two BIGINTs, does

问题 I couldn't really come up with a proper title for my question but allow me to present my case; I want to calculate a significance ratio in the form: p = 1 - X / Y Here X comes from an iterative process; the process takes a large number of steps and counts how many different ways the process can end up in different states (stored in a HashMap). Once the iteration is over, I select a number of states and sum their values. It's hard to tell how large these numbers are so I am intending to

问题 I have the following code at the head of a method: BigInteger foo = BigInteger.valueOf(0); BigInteger triNum = BigInteger.valueOf(0); //set min value to 1*2*3*4*5*...*199*200. BigInteger min = BigInteger.ONE; BigInteger temp = BigInteger.ZERO; for(int i=1; i<=200; i++) { temp = BigInteger.valueOf(i); min = min.multiply(temp); } System.out.println(min); while(triNum.compareTo(min) <= 0) { foo.add(BigInteger.ONE); triNum = triNum.add(foo); System.out.println("triNum: "+triNum); } This is

问题 How do i calculate the remainder for extremely large exponential numbers using java ? eg. (48^26)/2401 I tried using BIGINTEGER, however it gave the same output for large divisors.I'm not sure if BIG INTEGER can do this .I have tried all other PRIMITIVE data type.They seem to be insufficient. FYI it tried the following code: BigInteger a = new BigInteger("48"); a = a.pow(26); BigInteger b = new BigInteger("2401");//49*49 a = a.mod(b); System.out.println(a); I don't know why i got the same

问题 How do i calculate the remainder for extremely large exponential numbers using java ? eg. (48^26)/2401 I tried using BIGINTEGER, however it gave the same output for large divisors.I'm not sure if BIG INTEGER can do this .I have tried all other PRIMITIVE data type.They seem to be insufficient. FYI it tried the following code: BigInteger a = new BigInteger("48"); a = a.pow(26); BigInteger b = new BigInteger("2401");//49*49 a = a.mod(b); System.out.println(a); I don't know why i got the same

问题 I need to generate 512 bit BigInts, but I'm not sure which of the two below is true: 512 bits means 512 digits of 1010101010...001010 which are then converted to the decimal it represents? Or does it mean 512 digits of 0-9 , so basicly a 512-digit number with digits ranging from 0-9? Something like 12414124124....54543=512 digits. 回答1: From sourcecode, they are stored in an int array The magnitude of this BigInteger, in big-endian order: the zeroth element of this array is the most