模拟凸包的实现，只要随便点击一点，那么程序将自动寻找合适的点，将其连成凸包-simulation convex hull of achieving Just click 1:00, the process will automatically search for suitable spots, even as its convex hull

凸包测试，用std实现的凸包计算程序。可以作为一个类加入任何程序中。