Compilare: main.cpp: In function 'int main()': main.cpp:72:9: warning: unused variable 'now' [-Wunused-variable] int now = 0, before = 1; ^~~ main.cpp:72:18: warning: unused variable 'before' [-Wunused-variable] int now = 0, before = 1; ^~~~~~ main.cpp: In constructor 'InputReader::InputReader(const char*)': main.cpp:28:43: 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 member function 'void InputReader::advance()': main.cpp:56:47: 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); ^