摘要：
问题 C: Cities 题目描述 There are n cities in Byteland, and the ith city has a value ai. The cost of building a bidirectional road between two cities is the 阅读全文
摘要：
问题 A: Anagram 题目描述 Orz has two strings of the same length: A and B. Now she wants to transform A into an anagram of B (which means, a rearrangement of 阅读全文