The first line starts at the origin (0, 0) and the starting point of every subsequent line is the endpoint of the previous line.

第一行以原点(0,0)开始，而且下一段路的开始点同时也是上一段路的终结点。

youdao

If no objects are found for the endpoint, a collection of size zero (0) is returned.

如果找不到端点的物件，就会传回大小为零(0)的集合。

youdao