Compilare: user.cpp: In function ‘int main()’: user.cpp:26:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < numbers.size(); ++i) { ^ user.cpp:38:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < numbers.size(); ++i) cout << numbers[i]+1 << " "; ^