Compilare: user.cpp: In function ‘void print(std::vector<std::vector<std::vector<int, std::allocator<int> >, std::allocator<std::vector<int, std::allocator<int> > > >, std::allocator<std::vector<std::vector<int, std::allocator<int> >, std::allocator<std::vector<int, std::allocator<int> > > > > >)’: user.cpp:10: warning: comparison between signed and unsigned integer expressions user.cpp:11: warning: comparison between signed and unsigned integer expressions user.cpp:12: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:63: warning: comparison between signed and unsigned integer expressions user.cpp:80: warning: comparison between signed and unsigned integer expressions user.cpp:89: warning: comparison between signed and unsigned integer expressions user.cpp:98: warning: comparison between signed and unsigned integer expressions