How do i find the divisors of a number using c?

[Guest_imported]

How do i find the sum of the divisors of a number?

for example

for 12

1 + 2 + 3 + 4 + 6 =16

 

[ankan]

Find each of the divisors, and keep adding them to the running total.

int i, sum = 0, num = 12;

for(i=1; i <= num/2; i++)
if(!(num % i))
sum += i;

printf(&quot;%d&quot;, sum);

Bye.
Ankan. Please do correct me if I am wrong.

 

[Cagliostro]

Don't forget about performance:

int x;
.....
x=num/2; /* by the way num<<1 is much faster than num/2 */
for(i=1; i <= x; i++)
........ John Fill

ivfmd@mail.md

 

[ankan]

Thanks a lot, JohnFill, for reminding me. Will keep it in mind from now on.

And hey, I thought you could help me out at Thread205-112554. I'm just asking for a hint as to what's possibly wrong, maybe u can help. Please . Bye.
Ankan.

Please do correct me if I am wrong. s-)

 

[ankan]

Hey John,
I almost forgot, your:
&quot; /* by the way num<<1 is much faster than num/2 */&quot;
should be
&quot; /* by the way num>>1 is much faster than num/2 */&quot;
and to be on the safe side num should be declared unsigned.

Hope you agree.
Bye.
Ankan.

Please do correct me if I am wrong. s-)

 

[Cagliostro]

LOL sorry, my mistake John Fill

ivfmd@mail.md