Compilare: user.cpp: In function ‘int main()’: user.cpp:43:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < V.size(); i++) ^ user.cpp:47:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i > 0 && i < V.size() - 1) ^ user.cpp:61:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < V.size(); j++) ^