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:10: warning: comparison between signed and unsigned integer expressions user.cpp:10: warning: comparison between signed and unsigned integer expressions user.cpp:12: warning: comparison between signed and unsigned integer expressions user.cpp:14: 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> >, long long int)': user.cpp:26: warning: comparison between signed and unsigned integer expressions user.cpp: In function 'int main()': user.cpp:78: warning: comparison between signed and unsigned integer expressions user.cpp: In function 'std::vector<int, std::allocator<int> > fact(long long int)': user.cpp:48: warning: control reaches end of non-void function