Compilare: user.cpp: In function ‘std::vector<int, std::allocator<int> > solve(int)’: user.cpp:30: warning: comparison between signed and unsigned integer expressions user.cpp:37: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:60: warning: comparison between signed and unsigned integer expressions user.cpp:62: warning: comparison between signed and unsigned integer expressions