Compilare: user.cpp: In function ‘i64 get_optim()’: user.cpp:71:9: warning: unused variable ‘profitmax’ [-Wunused-variable] i64 profitmax(0); ^~~~~~~~~ user.cpp: In member function ‘void InputReader::advance()’: user.cpp:41:51: 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:15:47: 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); ^ user.cpp: In function ‘i64 get_optim()’: user.cpp:70:27: warning: ‘last’ may be used uninitialized in this function [-Wmaybe-uninitialized] i64 p(0), q(1 << 30), last; ^~~~