Write a C++ class to implement the BigInt data type defining signed integers (and operations on these integers) as large as 100 digits.

Here is the BigInt.h interface file for your class:

#ifndef _BIG_INT_H #define _BIG_INT_H namespace EGRE246 { 

 class BigInt{ public: 

 static const int MAX_DIGITS = 100; enum class Sign {NEG,ZERO,POS}; 

 BigInt(); // initializes to 0 BigInt(long long n); // exits program with error if too large BigInt(string s); // exits program with error if too large int getLen() const; 

 int cmp(BigInt& op2) const; // returns -1, 0, or 1 

 BigInt abs() const; // absolute value BigInt add(BigInt& op2) const; BigInt sub(BigInt& op2) const; BigInt mul(BigInt& op2) const; // optional BigInt div(BigInt& op2) const; // optional BigInt mod(BigInt& op2) const; // returns remainder; optional 

 friend std::ostream& operator <<(std::ostream& os, BigInt& n); 

 private: int digits[MAX_DIGITS]; Sign sign; int len; // num of digits not counting sign 

};

} #endif

bool extra_credit(); // return true if you do extra credit, false otherwise 

Your arithmetic functions should check for underflow or overflow where appropriate then print an error message and exit the program. You may assume that strings passed to the constructor BigInt(string) do not contain any illegal characters (where spaces, a + sign, and any non-digits are considered illegal). You will probably need to compile your program with the -std=c++11 command-line option.

The routines mul, div, and mod are optional but can be done for up to 15% extra credit. You must get all of these extra routines correct to receive the bonus (i.e. its all or nothing). Everyone should define the function extra credit to indicate if you have done the extra credit routines or not, e.g. implement it (but not as a member function of BigInt!) in the following manner:

bool extra_credit() { return true; // or return false if you did not do the extra credit 

}

Strings in C++ behave in a similar manner as C-style strings except they are not terminated by

\0. Here is a simple demo program illustrating some basic functionality:

#include

using namespace std; 

int main() { string s = "12345"; cout << "s = " << s << endl; for (int i = 0; i < s.length(); i++) { 

 cout << "s[" << i << "] = " << s[i] << endl; } 

 int n = s[4]-0; // convert a char to a digit 

 cout << "s[4] as an int = " << n << endl; }