摘要：
3126: [Usaco2013 Open]Photo Description Farmer John has decided to assemble a panoramic photo of a lineup of his N cows (1 <= N <= 200,000), which, as 阅读全文
摘要：
1688: [Usaco2005 Open]Disease Manangement 疾病管理 Description Alas! A set of D (1 <= D <= 15) diseases (numbered 1..D) is running through the farm. Farme 阅读全文