Compilare: main.cpp: In member function 'bool sof::operator<(sof) const': main.cpp:77:11: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses] if(d21==aux.d21) ^ main.cpp: In member function 'char input_parser::next()': main.cpp:38:65: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(this->buffer,1,max_load,this->fin),this->pos=0; ^