分数简化算法，浮点异常错误

Question

I am a beginner, and i am working on a C++ program that simlifies fractions, however I am getting this weird statement printed, it does not indicate an error, but it gives me the output "Floating point exception: 8".

Here is a snippet of my code(not yet complete), I do not ask for code and would prefer if my homework is not done for me, but I welcome logical suggestions to fix or improve the algorithms.

void Fraction::simplify()
{
  int i, x = 0, a[100], b[100];
  for (i = 0; i <= den; i++)
  {
    x = num % i;
    if (x == 0)
    {
      b[i] = i;  
    }
  }
}

Thanks a bunch.

Answer 1

x = num % i;

Computes the remaining of dividing num by i

But i = 0 in the first step, and you cannot devide by zero.