对数值很大、精度很高的数进行高精度计算是一类十分常见的问题。比如，对国债进行计算就是属于这类问题。 可以计算出R的n次方。-For great value, high precision the number of high-precision computing is a kind of very common problem. For example, the calculation of the national debt is part of this problem. R can ca