Uh, yeah thats unnecessary
Forgot to delete it. Thouht rand() was defined in there, but now that you mention it, it is defined in cstdlib.
Funny enough that the M$ compiler (cl.exe) compiled it without warning or error. Curious if gcc would compile it without an #include <cstdlib>.
About your professor... I hammered this together in like 5 minutes as I said to prove a point in a discussion with my friend :p. But then it is the best way of making the point that there is no real randomness on a PC. Only algorithms that generate them, but those can be influenced by the seed.
Thats why you can have the same world in Minecraft or Gnomoria by entering the same seed.
But I guess you know that if you study computer science or something.