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题目 ： Description The island nation of Flatopia is perfectly flat. Unfortunately, Flatopia has no public highways. So the traffic is difficult in Flato 阅读全文
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题目： Description You are a member of the space station engineering team, and are assigned a task in the construction process of the station. You are ex 阅读全文
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题目： Description There are N villages, which are numbered from 1 to N, and you should build some roads such that every two villages can connect to each 阅读全文
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题目： Description Farmer John has been elected mayor of his town! One of his campaign promises was to bring internet connectivity to all farms in the ar 阅读全文
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题目： Description The Head Elder of the tropical island of Lagrishan has a problem. A burst of foreign aid money was spent on extra roads between villag 阅读全文