Compilare: 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; ^ main.cpp: In member function 'int Node::height()': main.cpp:78:9: warning: nonnull argument 'this' compared to NULL [-Wnonnull-compare] if(this==NULL) ^~