STL算法实现的大整数加减法的程序， 能够进行正负数的加减，而且是动态数组的， 因此可以无限输入，这是本人这学期的大作业-STL algorithms and the largest integer addition and subtraction procedures, plus or minus a few to carry out addition and subtraction, but is a dynamic array, it can be unlimited importation, this is my semester of this operation