摘要：
Write a function that takes an unsigned integer and return the number of '1' bits it has (also known as the Hamming weight). Example 1: Example 2: Exa 阅读全文
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Given an integer, write a function to determine if it is a power of two. Example 1: Example 2: Example 3: M1: count how many bits are 1s, if # of 1s = 阅读全文
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Given a string which contains only lowercase letters, remove duplicate letters so that every letter appear once and only once. You must make sure your 阅读全文
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Given a list of directory info including directory path, and all the files with contents in this directory, you need to find out all the groups of dup 阅读全文
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Given an array A of positive integers, call a (contiguous, not necessarily distinct) subarray of A good if the number of different integers in that su 阅读全文
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Given a binary array data, return the minimum number of swaps required to group all 1’s present in the array together in any placein the array. Exampl 阅读全文