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CF915F-Imbalance Value of a Tree

CF915F-Imbalance Value of a Tree 题目: 题目描述: You are given a tree $ T $ consisting of $ n $ vertices. A number is written on each vertex; the number written on vertex $ i $ is $ a_{i} $ . Let’s denote the function $ I(x,y) $ as the difference between maximum and minimum value of $ a_{i} $ on a simple path

CF985F-Isomorphic Strings

CF985F-Isomorphic Strings 题目: 题目描述: You are given a string $ s $ of length $ n $ consisting of lowercase English letters. For two given strings $ s $ and $ t $ , say $ S $ is the set of distinct characters of $ s $ and $ T $ is the set of distinct characters of $ t $ . The