Compilare: user.cpp: In function ‘void UpdateFenwick(int, long long int)’: user.cpp:76:11: warning: statement has no effect [-Wunused-value] for (x; x <= MAXN; x += (x & -x)) ^ user.cpp: In function ‘long long int QueryFenwick(int)’: user.cpp:82:11: warning: statement has no effect [-Wunused-value] for (x; x > 0; x -= (x & -x)) ^ user.cpp: In member function ‘void InputReader::advance()’: user.cpp:38:51: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer, SIZE, 1, input_file); ^ user.cpp: In constructor ‘InputReader::InputReader(const char*)’: user.cpp:16:47: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer, SIZE, 1, input_file); ^