I hope this is an appropriate place to post this--I have no idea what happened.
I named a c++ file (a simple sudoku solver) "sudo.cpp" and then compiled it with "g++ sudo.cpp -o sudo" and ran "./sudo" from my directory /Code using Terminal. For some reason, moments after, Terminal froze, outputted strange text (I didn't have time to read it), and the computer crashed. Now I cannot boot (I get the blinking folder) and the hard drive does not even show up in Disk Utility when I start in Recovery Mode. Is there any way that the sudo command and the name of a file can conflict and somehow cause problems? I know it is a long-shot, but I can't imagine why a simple sudoku solver would otherwise (apparently) erase my hard-drive, and it seems very unlikely to be a coincidence.
(I was working on a MacBook Pro Mid-2014, 16 GB RAM, 512 GB Memory.)