public static double pow(double base, int exp)
{
  double retval = 1.0;
  if(exp == 0)
    return 1.0;
  else if(exp = 1)
    return base;
  else
  {
    retval = pow(base, exp/2)
    retval = retval * retval;
    if(base %2 == 1)
      retval = retval * base;
  }
  return retval;
}