Compilare: user.cpp: In function ‘double geometry::determinant(const std::vector<std::vector<double> >&)’: user.cpp:15:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In member function ‘double Poligon::get_area()’: user.cpp:48:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<points.size();++i){ ^