So this is my first complex program I have ever written, it's just called "Taschenrechner", which means calculator in english. It's not 100% original (last original change was 14.06.2019), I didn't knew git back then and therefor had no .gitignore or README.md. Also I messed with main.cpp, which has it's last modified timestamp set to 02.11.2021, but as far as I can see, it's still working in the same way as back then, so that's ok. It was developed using Code::Blocks IDE in school.
4 years later and I'm a full time developer.
The program is a CLI for doing math in a custom picked base (like base-10, base-16 but also base-36). It can work between base-2 and base-36 and can even do cross-base calculations. It supports addition, subtraction, multiplication and division. The calculation is performed on string base, so it's not limited by the size of any primitive.
Please do not rely on this to work, I was not a skilled programmer back then