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题目描述 At the main street of Byteland, there will be built n skyscrapers, standing sequentially one next to other. If look leftside right, sequence of t 阅读全文
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题目描述 There are n rectangle radar scanners on the ground. The sides of them are all paralleled to the axes. The i-th scanner's bottom left corner is sq 阅读全文
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题目描述 In the mathematical discipline of graph theory, the line graph of a simple undirected weighted graph G is another simple undirected weighted grap 阅读全文