add intro

CPlusPlus/intro/functions.h

@@ -0,0 +1,13 @@
+#pragma once
+
+#ifndef __FUNCTIONS_H__
+#define __FUNCTIONS_H__
+
+//void functionE() {}
+void functionF();
+void printArray(int numbers[], size_t count);
+void changeInt(int n);
+void changeIntPointer(int* pN);
+void changeIntReference(int& n);
+
+#endif // !__FUNCTIONS_H__