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D. Palindromic characteristics Palindromic characteristics of string s with length |s| is a sequence of |s| integers, where k-th number is the total n 阅读全文
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Island Transport Problem Description In the vast waters far far away, there are many islands. People are living on the islands, and all the transport 阅读全文
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Description Farmer John wants to set up a telephone line at his farm. Unfortunately, the phone company is uncooperative, so he needs to pay for some o 阅读全文
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A - Fence Repair Farmer John wants to repair a small length of the fence around the pasture. He measures the fence and finds that he needs N (1 ≤ N ≤ 阅读全文
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A. Key races A. Key races Two boys decided to compete in text typing on the site "Key races". During the competition, they have to type a text consist 阅读全文