摘要：
Description Consider a group of N students and P courses. Each student visits zero, one or more than one courses. Your task is to determine whether it 阅读全文
摘要：
Description 电子科大本部食堂的饭卡有一种很诡异的设计，即在购买之前判断余额。如果购买一个商品之前，卡上的剩余金额大于或等于5元，就一定可以购买成功（即使购买后卡上余额为负），否则无法购买（即使金额足够）。所以大家都希望尽量使卡上的余额最少。 某天，食堂中有n种菜出售，每种菜可购买一次。已 阅读全文
摘要：
Description Farmer John recently bought another bookshelf for the cow library, but the shelf is getting filled up quite quickly, and now the only avai 阅读全文