Compilare: user.cpp: In function ‘void update(int, int)’: user.cpp:43: warning: unused variable ‘bit’ user.cpp: In function ‘int sum(int)’: user.cpp:51: warning: unused variable ‘bit’ user.cpp: In function ‘int main()’: user.cpp:85: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:86: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result