C prob plz help

[wltjr1007]

#include <stdio.h>
#include <math.h>
int reverse(int a)
{
 int i=0,j, sum=0, scan;
 scan=a;
 while(a>0)
 {
  a=a/10;
  i++;
 }
 a=scan;
 for(j=0;j<i;j++)
 {
  sum+=(a%(int)pow(10,i-j))/(int)pow(10,i-j-1)*(int)pow(10,j);
 }
 return sum;
}
void main()
{
 int b;
 scanf("%d", &b);
 printf("%d\n", reverse(b));
}

I got the results right, but my professor wants me to finish the program without using math.h header or any functions.

Please help me!

[laserlight]

Hint: make use of modulo operation and integer division.

[GReaper]

Well, make a function equivalent to "pow". Since you're only using integers, it shouldn't be that hard.

EDIT: The use of no functions confuses me...

[memcpy]

If your professor is using void main(), you should show him this.

> The use of no functions confuses me...
I think he means no externally declared functions, like the <math.h> he mentioned.

Also, @op, you could also use a temporary char array, use modulo splitting to fill it (similar to what you have), and then take them out in reverse order.

[laserlight]

Also, @op, you could also use a temporary char array, use modulo splitting to fill it (similar to what you have), and then take them out in reverse order.

I think that that would be an unnecessary complication though. The use of multiplication is likely to be simpler.