BigInt

In C++, we can use large numbers by using the boost library. We can indeed use different datatypes like int128_t, int256_t, int1024_t etc. But in C no such features exist.

Therefore, to representing numbers in the range of -2⁶³-1 to 2⁶³-1 in C, we must build our own datatype called BigInt.

This program successfully implements BigInt in C with the addition and subtraction functionalities.

Addition:

• 44 + 55 = 99
• (-44) + 55 = 11
• 44 + (-55) = -11
• (-44) + (-55) = 9

Subtraction:

• 44 - 55 = -11
• (-44) - 55 = -99
• 44 - (-55) = 99
• (-44) - (-55) = 11