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E. Connected Components? You are given an undirected graph consisting of n vertices and edges. Instead of giving you the edges that exist in the graph 阅读全文
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C. Sum Balance Ujan has a lot of numbers in his boxes. He likes order and balance, so he decided to reorder the numbers. There are 𝑘 boxes numbered f 阅读全文
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D. 0 1 MST Ujan has a lot of useless stuff in his drawers, a considerable part of which are his math notebooks: it is time to sort them out. This time 阅读全文
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C. Tile Painting Ujan has been lazy lately, but now has decided to bring his yard to good shape. First, he decided to paint the path from his house to 阅读全文
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B2. Character Swap (Hard Version) This problem is different from the easy version. In this version Ujan makes at most 2𝑛 swaps. In addition, 𝑘≤1000, 阅读全文
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B1. Character Swap (Easy Version) This problem is different from the hard version. In this version Ujan makes exactly one exchange. You can hack this 阅读全文
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A. Maximum Square Ujan decided to make a new wooden roof for the house. He has 𝑛 rectangular planks numbered from 1 to 𝑛. The 𝑖 th plank has size � 阅读全文