Compilare: user.cpp: In function ‘int main()’: user.cpp:79:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v.size(); i++) ^ user.cpp:85:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v.size() ; i++) ^ user.cpp:105:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v.size(); i++) ^