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Given an array of integers and an integer k, find out whether there are two distinct indices i and j in the array such that nums[i] = nums[j] and the 阅读全文
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Given a non-empty array of integers, every element appears twice except for one. Find that single one. Note: Your algorithm should have a linear runti 阅读全文
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A linked list is given such that each node contains an additional random pointer which could point to any node in the list or null. Return a deep copy 阅读全文
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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 intege 阅读全文
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Given a pattern and a string str, find if str follows the same pattern. Here follow means a full match, such that there is a bijection between a lette 阅读全文