C++实现的模重复平方计算法，当处理两个大数的乘法时，容易产生溢出，得不到正确答案，打入利用模重复平方计算法就可以避免这个问题了。-Repeated square calculations C++ achieve the mold, prone to overflow when dealing with the multiplication of two large numbers, not the correct answer into the use of mold repeated squ