Compilare: user.cpp:4: warning: ISO C++ forbids declaration of ‘main’ with no type user.cpp: In function ‘int main()’: user.cpp:6: warning: ‘nr1’ may be used uninitialized in this function user.cpp:6: warning: ‘nr2’ may be used uninitialized in this function user.cpp:6: warning: ‘nr3’ may be used uninitialized in this function user.cpp:6: warning: ‘nr4’ may be used uninitialized in this function