Implementing the modulo operator as a function in C

Question

How can we implement the modulo operator as a function in C without using the operator?

Answer 1

Do an integer division followed by a multiplication, and subtract.

#include <stdio.h>
int main()
{
  int c=8, m=3, result=c-(c/m*m);
  printf("%d\n", result);
}

Answer 2

Here you go:

a % b = a - (b * int(a/b))

Answer 3

You could simulate x % y by repeatedly subtracting y from x and keeping track of the result. At each iteration, if the result is less than y, then you have your remainder, and can just return it.

Answer 4

Simple:

If the quotient a/b is representable, the expression (a/b)*b + a%b shall equal a

(C99 standard, 6.5.5/6).