Storing and printing 10+ digit integer in c++

Question

I'm using cout to print digits to the console. I am also storing values of up to 13+billion as a digit and doing computations on it. What data type should I use?

When I do the following:

int a = 6800000000;
cout << a;

It prints -1789934592.

thanks.

Answer 1

long long can hold up to 9223372036854775807. Use something like gmp if you need larger.

Answer 2

Use int64_t to guarantee you won't overflow. It is available from stdint.h.