Compilare: user.cpp: In member function ‘void InputReader::adv()’: user.cpp:25:54: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff, sizeof(char), BUFF_SIZE, fin); ^ user.cpp: In function ‘int main()’: user.cpp:131:26: warning: ‘f’ may be used uninitialized in this function [-Wmaybe-uninitialized] fout << '\n' << f << '\n'; ^~~~