Compilare: main.cpp: In function 'int main()': main.cpp:82:9: warning: unused variable 'st' [-Wunused-variable] int st = 0, dr = 0, last = 0, len = 0; ^~ main.cpp:82:17: warning: unused variable 'dr' [-Wunused-variable] int st = 0, dr = 0, last = 0, len = 0; ^~ main.cpp: In constructor 'InputReader::InputReader(const char*)': main.cpp:17:47: 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); ^ main.cpp: In member function 'void InputReader::advance()': main.cpp:39:51: 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); ^