Compilare: user.cpp: In function ‘std::vector<point> convex_hull(std::vector<point>)’: user.cpp:52:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1;i<points.size();i++) ^ user.cpp:66:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=2;i<points.size();i++){ ^ user.cpp: In function ‘void compute_corner()’: user.cpp:111:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<robot.size();i++){ ^ user.cpp: In function ‘std::vector<point> shrinked_polygon(std::vector<point>)’: user.cpp:123:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<points.size();i++) ^ user.cpp:124:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<robot.size();j++) ^ user.cpp: In function ‘bool intersects(const point&, const point&)’: user.cpp:145:48: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<shrinked_obstacles[i].size()-1;j++){ ^ user.cpp:158:48: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<shrinked_obstacles[i].size()-2;j++){ ^ user.cpp: In function ‘void compute_all_final_points()’: user.cpp:206:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<shrinked_obstacles[i].size();j++) ^