I'm trying to use the BN_* functions in OpenSSL. Specifically, I have the following code: #import <openssl/bn.h> BIGNUM * num = BN_new(); BN_set_word(num, 42); char * buffer = malloc((BN_num_bytes(num)+1) * sizeof(char)); buffer[BN_num_bytes(num)] = '\0'; int len = BN_bn2bin(num, buffer); printf("42 in binary is %s\n", buffer); Howev...
I am trying to compute 2^1000 (2 to the power of 1000) using c#. I need the value to all places. I've been scratching my head for a while now because I can't seem to figure out a way to achieve this in c#. Is there some kind of type that will store a number 300+ digits long, that I'm missing? :) Thanks ...
I have to check, if given number is divisible by 7, which is usualy done just by doing something like n % 7 == 0, but the problem is, that given number can have up to 100000000, which doesn't fit even in long long. Another constrain is, that I have only few kilobytes of memory available, so I can't use an array. I'm expecting the numbe...
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); }...
In .NET 4 beta 2, there is the new Numerics namespace with struct BigInteger. The documentation states that it is an immutable type, as I would have expected. But I'm a little confused by the post-increment operator (++). This defintely seems to mutate the value. The following while-loop works: static BigInteger Factorial(BigInteger ...
I'm trying to represent the result of an MD5 hash in the shortest possible string. It seems a waste to just turn it into a hex string and let G through Z go to waste. One idea I have had is getting the MD5 hash of my input as an array of bytes and constructing a BigInt with it. I can then call toString(36), and get the number as a base-...
I have a problem with the Java BigInteger class: I can't paste a large value into BigInteger. For example, let's say I want to assign a BigInteger to this number: 26525285981219105863630848482795 I cannot assign it directly, because the compiler thinks it's an integer: val bi = 26525285981219105863630848482795 //compile error But I...
I have this piece of code, which is not working: BigInteger sum = BigInteger.valueOf(0); for(int i = 2; i < 5000; i++) { if (isPrim(i)) { sum.add(BigInteger.valueOf(i)); } } The sum variable is always 0. What am I doing wrong? ...
I a m trying to generate a random prime number of type BigInteger, that is between an min and max value which I supply. I am aware of the BigInteger.probablePrime(int bitlength, random), but I am not sure how or even if the bitlength translates into a max/min value of the outputted prime. Thanks, Steven1350 ...
I need some division algorithm which can handle big integers (128-bit). I've already asked how to do it via bit shifting operators. However, my current implementation seems to ask for a better approach Basically, I store numbers as two long long unsigned int's in the format A * 2 ^ 64 + B with B < 2 ^ 64. This number is divisible by 2...
I know this question has probably been asked in this forum many times and in the web as well. I am asked to create an implementation of a big integer in c++, however there is a constraint that one of my constructor should take an int as an argument... so I am guessing there will be more than one non-default constructor... so my question ...
I am looking for a library for big integers but with fixed width (128 or 256 would be enough). The reason is I don't want any allocation on the heap. I tried to make them myself but implementing multiplication, division and modulo an efficient way seems to be quite a pain. Does this already exists somewhere ? Thanks ...
How do I do to handles some big positive integers (like 9,999,999,999) on Visual C++ 2008 on a 32-bit PC. Please give an example on declaring, printf, scanf of these big positive integers. Please consider using 9,999,999,999 in your example. ...
I was using the Pow function of the BigInteger class in F# when my compiler told me : This construct is deprecated. This member has been removed to ensure that this type is binary compatible with the .NET 4.0 type System.Numerics.BigInteger Fair enough I guess, but I didn't found a replacement immediately. Is there one? Sho...
I'm in need of an algorithm faster than the current normal python long multiplication , I tried to find a decent karatsuba implementation , but I can't. def main(): a=long(raw_input()) if(a<0): a=a*-1 a=((a*(a+1)/2)-1) print(-a) else: a=(a*(a+1))/2 print(a) main() As you see , it's nothing complica...
Hi, I want to write a BigInteger to a file. What is the best way to do this. Of course I want to read (with the program, not by human) it from an inputstream. Do I have to use an ObjectOutputStream or are there better ways? The purpose is to use as less bytes as possible. Thanks Martijn ...
The problem im facing with BigInteger when i try computing a string like "7+3" and then storing the result in a BigInteger variable, it throws a NumberFormat exception. Any pointers on how this can worked on? Eg: String ist="7+2"; java.math.BigInteger a = new java.math.BigInteger(ist); ...
Hi the below code print the biginteger to a file in decimal format ,how do i convert the code into printing binary data and hex data into the File instead ?? static void print_pos( FILE* f, bigint bi ) { if ( bi_compare( bi_copy( bi ), bi_10 ) >= 0 ) print_pos( f, bi_int_divide( bi_copy( bi ), 10 ) ); putc( bi_int_mo...
I was working on a scenario wherein i had to implement BODMAS in Java and the operands could have as many as 1000 digits. So i chose to implement it in the following manner - I converted the infix expression (expression on which BODMAS was to be implemented) to postfix And then i evaluated the postfix expression by parsing every BigInt...
Django now provides a BigIntegerField for use in django models (available in svn trunk and also 1.2 alpha-1 release). I need my django.contrib.auth.user model to have a BigIntegerField as its auto-incrementing primary key, whereas it currently uses an auto-incrementing IntegerField as its primary key. Also, wherever contrib.auth.user is...