Compilare: user.cpp: In function ‘std::vector<std::pair<double, double> > convexHull(std::vector<std::pair<double, double> >&)’: user.cpp:26:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < points.size(); ++i) ^ user.cpp:46:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < L.size(); ++i) ^ user.cpp: In function ‘int main()’: user.cpp:69:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < hull.size(); ++i) ^