Hello Everyone, I have been trying to solve this problem "Light Oj — 1313" for so long but could not find any solution. I can understand convex hull and point in polygon part than I got stuck every time. Can anybody tell me how to solve this problem. Thank you .

problem link : (http://www.aichengxu.com/other/3595766.htm) I am giving this link because you must have an account to open the main problem.