Compilare: user.cpp: In function ‘std::vector<int> add(std::vector<int>, std::vector<int>)’: user.cpp:23:50: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < b.size() - a.size() + 1; ++i) ^ user.cpp:27:54: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < a.size() - b.size() + 1; ++i) ^