创建一个大整数类HugeInteger，该类用一个40个元素的数组来存放一个大整数（最多不超过40位）。（1）定义几个大整数算术运算的成员函数，包括inputHugeInteger、outputHugeInteger、addHugeIntegers和substractHugeIntegers-Create a large integer class HugeInteger, with such an array of 40 elements to store a large integer (up to no more than 40). (1) define a few large integer arithmetic member functions, including inputHugeInteger, outputHugeInteger, addHugeIntegers and substractHugeIntegers