摘要：
A safari park（野生动物园）has K species of animals, and is divided into N regions. The managers hope to spread the animals to all the regions, but not the s 阅读全文
摘要：
A game of numbers has the following rules: at the beginning, two distinct positive integers are given by the judge. Then each player in turn must give 阅读全文
摘要：
The above picture is from Sina Weibo, showing May 23rd, 2019 as a very cool "Prime Day". That is, not only that the corresponding number of the date 2 阅读全文