biginteger

问题 Is it possible to parse a negative number into an unsigned value with Java's BigInteger ? So for instance, I'd to interpret -1 as FFFFFFFFFFFFFFFF . 回答1: If you are thinking of a two's complement, you must specify a working bit length. A Java long has 64 bits, but a BigInteger is not bounded. You could do something as this: // Two's complement reference: 2^n . // In this case, 2^64 (so as to emulate a unsigned long) private static final BigInteger TWO_COMPL_REF = BigInteger.ONE.shiftLeft(64);

问题 Is it possible to parse a negative number into an unsigned value with Java's BigInteger ? So for instance, I'd to interpret -1 as FFFFFFFFFFFFFFFF . 回答1: If you are thinking of a two's complement, you must specify a working bit length. A Java long has 64 bits, but a BigInteger is not bounded. You could do something as this: // Two's complement reference: 2^n . // In this case, 2^64 (so as to emulate a unsigned long) private static final BigInteger TWO_COMPL_REF = BigInteger.ONE.shiftLeft(64);

问题 I am currently doing the Go Lang tutorial, "Numeric Constants" to be precise. The example code starts with the following statement: const ( // Create a huge number by shifting a 1 bit left 100 places. // In other words, the binary number that is 1 followed by 100 zeroes. Big = 1 << 100 // Shift it right again 99 places, so we end up with 1<<1, or 2. Small = Big >> 99 ) The constant Big is obviously huge, and I am trying to print it and its type, like this: fmt.Printf("%T", Big) fmt.Println

问题 I am currently doing the Go Lang tutorial, "Numeric Constants" to be precise. The example code starts with the following statement: const ( // Create a huge number by shifting a 1 bit left 100 places. // In other words, the binary number that is 1 followed by 100 zeroes. Big = 1 << 100 // Shift it right again 99 places, so we end up with 1<<1, or 2. Small = Big >> 99 ) The constant Big is obviously huge, and I am trying to print it and its type, like this: fmt.Printf("%T", Big) fmt.Println

问题 I am using java and have to deal with numbers larger than long (which is 64 bits). What should I use? What is the size of BigInteger in java? 回答1: As you mentioned in your question, you should use BigInteger. They can be as large as you need - until you run out of memory. 回答2: What is the size of BigInteger in java? That's a little bit tricky. The problem is that there is no clear specification of the limit in the javadocs. The class uses an int[] to represent the magnitude. This means it

问题 I am using java and have to deal with numbers larger than long (which is 64 bits). What should I use? What is the size of BigInteger in java? 回答1: As you mentioned in your question, you should use BigInteger. They can be as large as you need - until you run out of memory. 回答2: What is the size of BigInteger in java? That's a little bit tricky. The problem is that there is no clear specification of the limit in the javadocs. The class uses an int[] to represent the magnitude. This means it

问题 I worked on a code for an RSA algorithm and it returns the incorrect number, which happens to be huge. I am sure I coded everything right except for one line I was not sure about. I did not know how to solve for the private key in the RSA, and just winged it (I saw someone code d = e.modInverse(m); where d is the private key, e is the public key, and m is (p-1)*(q-1). I dont understand how the modInverse method works though. long story short, how do you actually solve for the 'd' without

问题 I worked on a code for an RSA algorithm and it returns the incorrect number, which happens to be huge. I am sure I coded everything right except for one line I was not sure about. I did not know how to solve for the private key in the RSA, and just winged it (I saw someone code d = e.modInverse(m); where d is the private key, e is the public key, and m is (p-1)*(q-1). I dont understand how the modInverse method works though. long story short, how do you actually solve for the 'd' without

问题 I try some examples from Rosettacode and encounter an issue with the provided Ackermann example: When running it "unmodified" (I replaced the utf-8 variable names by latin-1 ones), I get (similar, but now copyable): $ perl6 t/ackermann.p6 65533 19729 digits starting with 20035299304068464649790723515602557504478254755697... Cannot unbox 65536 bit wide bigint into native integer in sub A at t/ackermann.p6 line 3 in sub A at t/ackermann.p6 line 11 in sub A at t/ackermann.p6 line 3 in block

问题 I'm trying to solve Fibonacci using java, but my code takes so long with big numbers. Problem Description Task. Given an integer 𝑛, find the last digit of the 𝑛th Fibonacci number 𝐹𝑛 (that is, 𝐹𝑛 mod 10). Input Format. The input consists of a single integer 𝑛. Constraints. 0 ≤ 𝑛 ≤ 10⁷. Output Format. Output the last digit of 𝐹𝑛 . My code: public class FibonacciLastDigit { private static int getFibonacciLastDigitNaive(int n) { if (n <= 1) { return n; } BigInteger first = BigInteger.ZERO;