抓不住Jerry的Tom

摘要： There are n houses in the village and some bidirectional roads connecting them. Every day peole always like to ask like this "How far is it if I want 阅读全文

摘要： Boxes There are NN boxes, indexed by a number from 11 to NN. Each box may (or not may not) be put into other boxes. These boxes together form a tree s 阅读全文