Compilare: user.cpp: In function 'std::vector<int, std::allocator<int> > add(std::vector<int, std::allocator<int> >, std::vector<int, std::allocator<int> >)': user.cpp:18: warning: comparison between signed and unsigned integer expressions user.cpp:18: warning: comparison between signed and unsigned integer expressions user.cpp:20: warning: comparison between signed and unsigned integer expressions user.cpp:21: warning: comparison between signed and unsigned integer expressions user.cpp: In function 'std::vector<int, std::allocator<int> > mult(std::vector<int, std::allocator<int> >, int)': user.cpp:32: warning: comparison between signed and unsigned integer expressions user.cpp:34: warning: comparison between signed and unsigned integer expressions