I'd like to make it clear that I don't have any serious intentions to work on this. I only uploaded it for archival purposes.

Currently things that I'd like it to have:

1. A way to restrict the .add() function to only take the input alphabet. Currently it's just up to you to uphold the contract. As a hack, I have decided to fail the insertion if the char isn't in the input alphabet vector. But I'd like this to be a compile-time error.
2. A way to construct DFA as well.

Also, I'm not sure if this impl is correct. It sounds correct, but it might not be. I wrote this in an hour, after procrastinating for months, when I first was hyped about it learning it in my Finite Automata classes.