Okay, so you want to calculate a^b mod m. First we’ll take a naive approach and then see how we can refine it. First, reduce a mod m. That means, find a number a1 so that 0 <= a1 < m and a = a1 mod m. Then repeatedly in a loop multiply by a1 … Read more
For some number y and some divisor x compute the quotient (quotient) and remainder (remainder) as: var quotient = Math.floor(y/x); var remainder = y % x;
Both definitions of modulus of negative numbers are in use – some languages use one definition and some the other. If you want to get a negative number for negative inputs then you can use this: int r = x % n; if (r > 0 && x < 0) { r -= n; } … Read more
I always use my own mod function, defined as int mod(int x, int m) { return (x%m + m)%m; } Of course, if you’re bothered about having two calls to the modulus operation, you could write it as int mod(int x, int m) { int r = x%m; return r<0 ? r+m : r; } … Read more
Actually, it’s not true that 3.5 % 0.1 is 0.1. You can test this very easily: >>> print(3.5 % 0.1) 0.1 >>> print(3.5 % 0.1 == 0.1) False In actuality, on most systems, 3.5 % 0.1 is 0.099999999999999811. But, on some versions of Python, str(0.099999999999999811) is 0.1: >>> 3.5 % 0.1 0.099999999999999811 >>> repr(3.5 % … Read more
The % does two things, depending on its arguments. In this case, it acts as the modulo operator, meaning when its arguments are numbers, it divides the first by the second and returns the remainder. 34 % 10 == 4 since 34 divided by 10 is three, with a remainder of four. If the first … Read more
Instead of the modulo operator, which has slightly different semantics, for non-negative integers, you can use the remainder operator %. For your exact example: if ((a % 2) == 0) { isEven = true; } else { isEven = false; } This can be simplified to a one-liner: isEven = (a % 2) == 0;
The % operator is for integers. You’re looking for the fmod() function. #include <cmath> int main() { double x = 6.3; double y = 2.0; double z = std::fmod(x,y); }
You do this using the modulus operator, % n % k == 0 evaluates true if and only if n is an exact multiple of k. In elementary maths this is known as the remainder from a division. In your current approach you perform a division and the result will be either always an integer … Read more
Unlike C or C++, Python’s modulo operator (%) always return a number having the same sign as the denominator (divisor). Your expression yields 3 because (-5) / 4 = -1.25 –> floor(-1.25) = -2 (-5) % 4 = (-2 × 4 + 3) % 4 = 3. It is chosen over the C behavior because … Read more