Compilare: main.cpp: In function 'void dfs(int)': main.cpp:89:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[nod].size();i++){ ~^~~~~~~~~~~~~~ main.cpp: In member function 'char input_parser::next()': main.cpp:54:65: 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; ^