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The task is really simple: given N exits on a highway which forms a simple cycle, you are supposed to tell the shortest distance between any pair of e 阅读全文
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Shuffling is a procedure used to randomize a deck of playing cards. Because standard shuffling techniques are seen as weak, and in order to avoid "ins 阅读全文
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Being unique is so important to people on Mars that even their lottery is designed in a unique way. The rule of winning is simple: one bets on a numbe 阅读全文
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To prepare for PAT, the judge sometimes has to generate random passwords for the users. The problem is that there are always some confusing passwords 阅读全文
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Given two strings S1 and S2, S=S1−S2 is defined to be the remaining string after taking all the characters in S2 from S1. Your task 阅读全文
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Behind the scenes in the computer's memory, color is always talked about as a series of 24 bits of information for each pixel. In an image, the color 阅读全文
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If you are a fan of Harry Potter, you would know the world of magic has its own currency system -- as Hagrid explained it to Harry, "Seventeen silver 阅读全文