Here are some of Hong Kong Computer Olympiad in Informatics. If you have time, you can try it. Personally think that these topics are very tested. If you want to write a way, think flexibly, apply to some shortcuts, do you want to do it.
2003: Primary Group Senior Group 2002: Primary Group Senior Group 2001: Primary Group Senior Group - Wenhe: http://blog.blueshop.com.tw/marcus/archive/2004/18/831. ASPX
