Thanks. I got total 12 cases. This time, we followed the order.

来源: 于 2010-10-17 14:24:19 [旧帖] [给我悄悄话] 本文已被阅读：次

1) OOOA   OOAO

2) OORA   OROA

3) OOAA   OAOA

4) ORRA   ORAR

5) ORAA   OARA

6) OAAA  

7) RRRR

We say yes for isomorphism.