Hi, I have a code in which i am computing x % 25. x always takes a positive value but its dynamic range is large. I found out that this particular code piece of computing a x % 25 is taking large cycles. I need to optimize it. Pre-computed lookup table is ruled out due to the possible large memory size of the table. As second appro...
I need to be able to calculate (a^b) % c for very large values of a and b (which individually are pushing limit and which cause overflow errors when you try to calculate a^b). For small enough numbers, using the identity (a^b)%c = (a%c)^b%c works, but if c is too large this doesn't really help. I wrote a loop to do the mod operation manu...
So I thought that negative numbers, when mod'ed should be put into positive space... I cant get this to happen in objective-c I expect this: -1 % 3 = 2 0 % 3 = 0 1 % 3 = 1 2 % 3 = 2 But get this -1 % 3 = -1 0 % 3 = 0 1 % 3 = 1 2 % 3 = 2 Why is this and is there a workaround? ...
I want to print modulus operator as it is over the command line: E.g this is how the output should look like: 1%2 2%4 or 30% 40% I am using the print statement like this: print 'computing %s % %s' % (num1, num2) Its throwing the default error: TypeError: not all arguments converted during string formatting For now I am ...
Duplicate of Weird Objective-C Mod Behavior I'm trying to mod an integer to get an array position so that it will loop round. Doing i % arrayLength works fine for positive numbers but for negative numbers it all goes wrong. so i need an implementation of int GetArrayIndex(int i, int arrayLength) such that GetArrayIndex(-4, 3) == 2...
To check for odd and even integer, is the lowest bit checking more efficient than using the modulo? >>> def isodd(num): return num & 1 and True or False >>> isodd(10) False >>> isodd(9) True ...
So I am porting a VBA application to PHP and ran into this wonderful little nugget of code: expr1 = expr2 Mod expr3 = 0 I thought it was behaving like a ternary operator but when I broke it down to simple if then statements the outcome was not as expected. So I ask the brilliant stack**overflow** community to help me out and put it in...
Ok I have two functions the first of which looks like so: let dlth x = float (x.ToString().Length) which takes a float and returns the number of digits, that part works fine. The second function looks like this: let droot x = ((x ** (1./(dlth x))) % 1.) which takes a float and raises it to a power equal to 1.0/(number of digits), ...
I have two CGFloat values, and want to calculate the modulo result. Or in other words: I want to know what's left if valueA is placed as much as possible into valueB. So I just tried: CGFloat moduloResult = valueB % valueA; the compiler complains about the % and tells me: "invalid operands to binary %". Any idea? ...
I'm in a very performance-sensitive portion of my code (C#/WPF), and I need to perform a modulus operation between two System.TimeSpan values in the quickest way possible. This code will be running thousands of times per second, and I would very much prefer to avoid using a manual loop calculation - at all costs. The idea of a modu...
This is very strange to me: irb(main):012:0> "100.7".to_f.modulo(1) => 0.700000000000003 Why the 3 at the end? irb(main):019:0> "10.7".to_f.modulo(1) => 0.699999999999999 Same thing here...we are only getting the remainder of this value divided by one. It should be exact. ...
I'm embarrassed to ask such a simple question. My term does not start for two more weeks so I can't ask a professor, and the suspense would kill me. 2/4 = .5 so why does 2 mod 4 = 2? Sorry if I'm missing something obvious. Thanks! ...
Hello :) I have a 128 byte (1024 bit) modulus (in a byte array format) and my exponent (also in a byte array format). I need to create a 128 bytes byte array representing the public key. According to Wikipedia, "The public key consists of the modulus n and the public (or encryption) exponent e." But that doesn't tell me how to mix both...
My problem is to compute (g^x) mod p quickly in JavaScript, where ^ is exponentiation, mod is the modulo operation. All inputs are nonnegative integers, x has about 256 bits, and p is a prime number of 2048 bits, and g may have up to 2048 bits. Most of the software I've found that can do this in JavaScript seems to use the JavaScript Bi...
I need to calculate (a/b) mod m where a and b are very large numbers. What I am trying to do is to calculate (a mod m) * (x mod m), where x is the modular inverse of b. I tried using Extended Euclidean algorithm, but what to do when b and m are not co-prime? It is specifically mentioned that b and m need to be co-prime. I tried using ...
I'm messing with the modulo operation in python and I understand that it will spit back what the remainder is. But what if the first number is smaller than the second? for instance 2 % 5 the answer is 2. How does that work? 2/5 = .4! ...
Hello, I'm currently writing a quick custom encoding method where I take a stamp a key with a number to verify that it is a valid key. Basically I was taking whatever number that comes out of the encoding and multiplying it by a key. I would then multiply those numbers to the deploy to the user/customer who purchases the key. I wanted...
int main() { int i,j; for (i=1; i<=25; i++) { for (j=2; j<= i/2; j++) if (!(i%j)) break; if (j>i/2) cout << i << "\n"; } return 0; } This program (not written by me) outputs the prime numbers from 1 to 25, including 1 even though 1 isnt prime. I am having trouble with this line: if (!(i%j)) break; Does this say "not modu...
I have to write a program which reads in 3 numbers (using input boxes), and depending on their values it should write one of these messages: All 3 numbers are odd OR All 3 numbers are even OR 2 numbers are odd and 1 is even OR 1 number is odd and 2 are even This is what I have so far: import javax.swing.JOptionPane; class program3 ...
I have a function I've written to convert from a 64-bit integer to a base 62 string. Originally, I achieved this like so: char* charset = " 0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"; int charsetLength = strlen(charset); std::string integerToKey(unsigned long long input) { unsigned long long num = input; st...