将整数的各个数位存储为一个长度为四十的字符数组中各个元素。能够进行四十位的整数的加减法-Create a class HugeInteger that uses a 40-element array of digits to store integers as

large as 40 digits each (e.g. 8783 is stored as an array of {3,8,7,8,0,0,0,....} ), and use another

boolean member to denote whether it is positive or negative. .

a. Provide member functions input, output, add,substract. Check if these

operations cause overfl ow, i.e. larger than 40 digits, or underfl ow, i.e. less than 0.

b. For comparing HugeInteger objects, provide functions isEqualTo, isNotEqualTo,

isGreaterThan, isLessThan, isGreaterThanOrEqualTo and

isLessThanOrEqualTo-- each of these is a predicate function that simply returns

true if the relation holds between two huge integers and returns false otherwise.

c. Also provide a predicate function isZero.

d. Write a driver program to test class HugeInteger.