Compilare: main.cpp: In function 'std::__cxx11::string go_visit(int)': main.cpp:13:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<nod[pos].size();j++) ^ main.cpp:15:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<nod[pos].size();j++) ^ main.cpp: In function 'int main()': main.cpp:43:21: warning: 'where' may be used uninitialized in this function [-Wmaybe-uninitialized] sir=go_visit(where); ^