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题目 Count the number of prime numbers less than a non negative number, n. Example: Input: 10 Output: 4 Explanation: There are 4 prime numbers less than 阅读全文
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题目 Remove all elements from a linked list of integers that have value val. Example: Input: 1 2 6 3 4 5 6, val = 6 Output: 1 2 3 4 5 解法 思路 思路不难。。。就是很繁琐 阅读全文
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题目 Write an algorithm to determine if a number is "happy". A happy number is a number defined by the following process: Starting with any positive int 阅读全文
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题目 You are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed, the only constraint stopping 阅读全文