Compilare: main.cpp: In function 'std::__cxx11::string unite(std::__cxx11::string, std::__cxx11::string)': main.cpp:13:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(inda>=0 and indb<b.size() and a[inda]==b[indb]) ~~~~^~~~~~~~~ main.cpp:19:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(indb<b.size() and b[indb]==ch) ~~~~^~~~~~~~~ main.cpp:29:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=lastb;i<b.size();++i) ~^~~~~~~~~