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Given a non-empty, singly linked list with head node head, return a middle node of linked list. If there are two middle nodes, return the second middl 阅读全文
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A strobogrammatic number is a number that looks the same when rotated 180 degrees (looked at upside down). Write a function to determine if a number i 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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Design a logger system that receive stream of messages along with its timestamps, each message should be printed if and only if it is not printed in t 阅读全文
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Given a list of strings words representing an English Dictionary, find the longest word in words that can be built one character at a time by other wo 阅读全文
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Given two lists Aand B, and B is an anagram of A. B is an anagram of A means B is made by randomizing the order of the elements in A. We want to find 阅读全文