摘要：
1008 Elevator （20 分） The highest building in our city has only one elevator. A request list is made up with N positive numbers. The numbers denote at 阅读全文
摘要：
1004 Counting Leaves （30 分） A family hierarchy is usually presented by a pedigree tree. Your job is to count those family members who have no child. I 阅读全文