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PROBLEM http://www.oi.edu.pl/old/ceoi2004/problems/jou.pdf 分析 这题属于需要一些思考的题目。对于这道题目，我们要了解到这个图其实就是一棵树。如何想到这是树？题目中又这样几句话： There are n cities in Byteland. 阅读全文
摘要：
PROBLEM Tired of the cold winter weather on her farm, Bessie the cow plans to fly to a warmer destination for vacation. Unfortunately, she discovers t 阅读全文