Compilare: user.cpp:8: warning: ISO C++ forbids declaration of ‘main’ with no type user.cpp: In function ‘int main()’: user.cpp:24: warning: format ‘%d’ expects type ‘int’, but argument 3 has type ‘long int’ user.cpp:15: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result