Code

 Header...
//
// Return base to the power of exponent. 
// If base == zero and exponent < zero, 
// print a warning and return zero
//
 double mypow(double base,int exponent){
   ... 

»  double result=1.0;

»  if (base==0.0&&exponent<0) {
»    printf("WARNING: mypow called with zero base and negative exponent\n");
»    return 0.0;
  }

»  while (exponent>0) {
»    result*=base;
»    --exponent;
  }
  
»  while (exponent<0) {
»    result/=base;
»    ++exponent;
  }
  
»  return result;
}

 int main(){
   ... 

»  printf("Base: %g\n", mypow(6.1, 3));

»  return 0;
}

Data