optimize add and sub about break_infinity.js HOT 2 OPEN

  public static BigNum operator +(BigNum bn1, BigNum bn2)
  {
    long num = Math.Abs(bn1.Exponent - bn2.Exponent);
    if (bn1.Exponent > bn2.Exponent)
    {
      bn2.Base /= Math.Pow(10.0, (double) num);
      bn2.Exponent += num;
    }
    else if (bn1.Exponent < bn2.Exponent)
    {
      bn1.Base /= Math.Pow(10.0, (double) num);
      bn1.Exponent += num;
    }
    return new BigNum(bn1.Base + bn2.Base, bn1.Exponent);
  }