Compilare: main.cpp:6:0: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas] #pragma GCC optimization ("O3") main.cpp: In member function 'void InputReader::advance()': main.cpp:124:38: 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); ^ main.cpp: In constructor 'InputReader::InputReader(const char*)': main.cpp:102:37: 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); ^