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Bichrome Tree 题目描述 We have a tree with N vertices. Vertex 1 is the root of the tree, and the parent of Vertex i (2≤i≤N) is Vertex Pi.To each vertex in 阅读全文
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Small Multiple 题目描述 Find the smallest possible sum of the digits in the decimal notation of a positive multiple of K.Constraints2≤K≤105K is an integer 阅读全文
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Restoring Road Network In Takahashi Kingdom, which once existed, there are N cities, and some pairs of cities are connected bidirectionally by roads. 阅读全文