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Description: Given a non-empty array of integers, return the third maximum number in this array. If it does not exist, return the maximum number. The 阅读全文
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Description: We define the Perfect Number is a positive integer that is equal to the sum of all its positive divisors except itself. Now, given an int 阅读全文
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Description: Given an integer, return its base 7 string representation. Example 1: Example 2: Note: The input will be in range of [-1e7, 1e7]. Solutio 阅读全文
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Description Given a string date representing a Gregorian calendar date formatted as YYYY-MM-DD, return the day number of the year. Example 1: Example 阅读全文