Compilare: user.cpp: In function ‘void update(int)’: user.cpp:10: warning: unused variable ‘i’ user.cpp: In function ‘int main()’: user.cpp:64: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:65: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:67: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:69: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:73: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result