I hate to break it to you, that is typical C. But not because of the reason he provided, because you can use printf() in both C and C++.
But there is nothing C++ specific in there; no references, classes, object orientation, or instantiation. In other words, it is C, because you can plug this code into an ANSI C compiler and it would still run.
And C# has nothing to do with this; in fact that is incorrect C# syntax.
EDIT: And by the way, both C and C++ use the same header include system.
This is a telltale sign of C:
#include <stdio.h>
This is a telltale sign of C++:
#include <iostream> //note there is no .h
using namespace ...; //C does not use namespaces