实现长度80位内的大数加法~~代码以c来实现，在tc下编译通过，有详细的注释-achieved within 80 lengths of large numbers Adder ~ ~ c code to be achieved under the tc compile a detailed Notes

大数加法减法乘法只支持大数减小数对乘积的结果进位 -Large number of add and subtract

大整数加减，加法很容易，减法的功能为输入两个大整数相减，考虑到了小数减大数结果前加符号，然后进位等功能。-Large integer addition and subtraction, addition is easy, subtraction functions as an input two large integers subtraction, taking into account the plus sign in front of large numbers of decimal su