Compilare: user.cpp: In function ‘bool OK(std::__cxx11::string, std::__cxx11::string)’: user.cpp:16:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size();i++) ~^~~~~~~~~ user.cpp:21:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(ind == d.size())return true; ~~~~^~~~~~~~~~~ user.cpp:29:1: warning: control reaches end of non-void function [-Wreturn-type] } ^