Compilare: main.cpp: In function 'int main()': main.cpp:15:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<S.size();i++) ~^~~~~~~~~ main.cpp:17:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<S.size();i++) ~^~~~~~~~~ main.cpp:21:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i==S.size()-1) S.push_back(0); ~^~~~~~~~~~~~ main.cpp:28:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<S.size();i++) g<<S[i]; ~^~~~~~~~~