剩余类加群Zn的所有子群的一种求法

A Way to Get All the Subgroups of Residue Class Adding-group Zn

怎样找出剩余类加群Zn的所有子群,通常的方法是通过zn的加法表来求得。

How to find out all the subgroups of the residue class adding-group Zn,the usual way is to add Zn.A more simpler method has deen suggested in the following.