Compilare: user.cpp: In function ‘int main()’: user.cpp:8: warning: unused variable ‘inc’ user.cpp:23: warning: unused variable ‘sf’ user.cpp:9: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:10: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:11: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result