Compilare: user.cpp: In function ‘int main()’: user.cpp:35: warning: unused variable ‘j’ user.cpp:36: warning: unused variable ‘lo’ user.cpp:36: warning: unused variable ‘hi’ user.cpp:28: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:29: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:39: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:50: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result