摘要：
You are a member of the space station engineering team, and are assigned a task in the construction process of the station. You are expected to write 阅读全文
摘要：
You are assigned to design network connections between certain points in a wide area. You are given a set of points in the area, and a set of possible 阅读全文
摘要：
The Head Elder of the tropical island of Lagrishan has a problem. A burst of foreign aid money was spent on extra roads between villages some years ag 阅读全文