System dependent limitations for code

Question

With the function:

int five(int n)
{
    if ((n%5)==0)
        return 1;
    else
        return 0;
}

Why are the limitations of this positive numbers only even if there is no remainder?

I don't understand what you mean. It works for all `int` values. (Better would be `return n % 5 == 0;`, though) — Daniel Fischer, Oct 12 '12 at 18:47

score 2 · Answer 1 · answered Oct 12 '12 at 18:49

2

for n == -2, some hardware will compute n%5 as 3, while other hardware evaluates it as 2. To accommodate that , the standard leaves % ambiguous for negative values.

answered Oct 12 '12 at 18:49

William Pursell

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4

“the standard leaves % ambiguous for negative values.” Not since C99. Division rounds towards zero and modulo is defined such that `(a/b)*b + a%b` equals `a`. (6.5.5:6) – Pascal Cuoq Oct 12 '12 at 18:51
by mathematical definition -2%5 == 3 == (-2+5)%5, http://mathforum.org/library/drmath/view/52343.html – 0x90 Oct 12 '12 at 18:55
2

@0x90 `%` operator in C is a remainder and not a modulo operator. – ouah Oct 12 '12 at 18:58

System dependent limitations for code

1 Answers1