Yes and no. The code is correct and will do what you want. Please ensure then that the member "vertex_numbers" in the struct "TURRET" is char* as well.

But I wouldn't recommend using chars for this purpose. char implies that you want to use letters and char* is normally used to as an array of letters and hence a string (not a game studio STRING!). You can use short or int values for the purpose as well. Please note that his not about correctness or technical limitations but just about aesthetics and code readability.