在C语言中包含一个头文件UbigraphAPI.h，便可以像往常一样用循环语句“画”一个环，展示出图论模型的三维结构（需下载Ubigraph软件）-Contains a header file UbigraphAPI.h in the C language can be as usual loop " paint" a ring, demonstrating the three-dimensional structure of the graph theory model (s