I was so happy to see you spot the missing “const” while defining GetBullCows nearer the end of the lecture.
I’m using Visual Studio 2019 and it was complaining that GetBullCows declaration was incompatible but wasn’t seeing it your VS Code so I spent way too long looking through my code compared to what was on screen. Luckily I had come to the same conclusion that the const was missing from the end.