decimal to binary with exponent function

/* john pfeiffer 15jan06    converts a positive decimal number to up to an 8 digit binary number 
  2^0 = 1, 2^1 = 2, 2^2 = 4, 2^3 = 8, 2^4 =16, 2^5 =32
  case 0=0, case 1=0, case 2=1, case 3=1, case 4 = 2

fixed/updated jan09
*/
#include <stdio.h>
#include <stdlib.h> 
/* stdlib for abs */

/* pow returns float (for neg values!), exponent function handles positive exp, exp=0, and even negative exp.
*/

float pow(int base, int exponent)
{   
    int i=1;
    float result=1;
    int negexp = 0;

    if( exponent !=0 )          /* special case, exp = 0, just return 1  */
    {   if( exponent < 0 )      /* negative exponent */
        {   negexp = 1;
            exponent = abs(exponent);
        }
        for(i=1; i < exponent+1; i++)
        {   result = result * ((float)base);  }
    }
    if( negexp == 1 )      /* negative exponents create small numbers */
    {   result = (1 / result);    }

    return result;
}/* end func pow */


int main(int argc, char* argv[])
{   
    int decimal = 35;
    int i=0;
    int k=0;
    int binary_digits[8];       /* up to 8 binary digits? */

    for(k=0; k<8; k++)
    {   binary_digits[k] = 0;  }

    printf("decimal: %d\n",decimal);        /* print before we transform dec */

    if( decimal != 0)    /* if dec == 0 then we can just print our default 0's */
    {   do
        {   i=1;
            if( decimal == 1 )                      /* special case of 2^0 = 1 */
            {   binary_digits[i] = 1;    }
            else
            {   while( pow(2,i) <= ((float)decimal) )   /* pow returns float */
                {   i++;    }                   
                binary_digits[i-1] = 1;                    
            }
            decimal = decimal - ((int)pow(2,i-1));      
        }while( decimal > 0 );
    }

    printf("binary: ");

    for(k=7; k>=0; k--)
    {   printf("%d", binary_digits[k]);  }

    printf("\n");

    printf("\nexample of pow function and negative exponents\n");
    printf("\n%d^%d=%f\n",3,5,pow(3,5));
    printf("\n%d^%d=%f\n",3,-2,pow(3,-2));


    return 0;
}/* end main */