(Hunan Normal University)
Author: Shen Wenxuan (competition god, world-renowned, senior coach of China Mathematical Olympics, thanks to him, the middle school attached to Hunan Normal University won the first place in the national mathematics competition).
Zhang Yao (competition expert, commentator of American Mathematical Review, senior coach of China Mathematical Olympics)
Wu (this person has almost only one title: competition expert)
This set of books is the best competition counseling materials I know, and many exercises are very practical. In addition, I suggest you buy a scientifically published book "From Mathematics Competition to Competition Mathematics" by Zhu Huawei. This book is very enlightening and can help you understand the competitions (junior high school, senior high school, American League, American Invitational Tournament, IMO, etc. ), but there are also detailed explanations and problem-solving exercises.
There is no such thing as a competition. Some simple books are worse than textbooks. Don't think about it. Where there are setbacks, there must be success. Even if you can't get into many places in the country, it will be good for your future math study and college entrance examination. Universities like students who accept competitions, because some contents of universities have been studied before the competitions. )