点击打开链接 Jerry, a middle school student, addicts himself to mathematical research. Maybe the problems he has thought are really too easy to an expert. But as an amateur, especially as a 15-year-old

任意给定一个多边形，判断它是凸还是凹。多边形的顶点以逆时针方向的序列来表示。 %%%%%%%%%%%%%%%% #include #include struct point { double x,y; }g[15000]; int ploy(point a,point b,point c) { int d=(c.x-a.x)*(b.y-a.y)-(b.x-a.x)*(c.y-a.y);