I am not very comfortable with using C++ but am very familiar with Java. I am trying to construct an RSA encryption. The issue I am running into is when numbers get large. I am currently using uint64_t for all of my numbers, but at one point the numbers get too big and my final answer is different than what it should be.
Another issue is converting text into ascii. I want it so that if I type 'a', it would convert to 97.

Thank you very much for the help
Dennis