Compilare: user.cpp: In function ‘int main()’: user.cpp:18:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < S.size(); i ++) ^ user.cpp:39:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < S.size(); i ++) ^ user.cpp:53:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < V.size(); i ++) ^