344. Reverse StringWrite a function that takes a string as input and returns the string reversed. Example 1: Input: “he

268. Missing NumberGiven an array containing n distinct numbers taken from 0, 1, 2, ..., n, find the one that is missing

231. Power of TwoGiven an integer, write a function to determine if it is a power of two. Example 1: Input: 1 Output: t

201. Bitwise AND of Numbers RangeGiven a range [m, n] where 0 <= m <= n <= 2147483647, return the bitwise AND o

191. Number of 1 BitsWrite a function that takes an unsigned integer and return the number of ‘1’ bits it has (also know

182. Duplicate EmailsSQL架构 Create table If Not Exists Person (Id int, Email varchar(255)) Truncate table Person insert i

136. Single NumberGiven a non-empty array of integers, every element appears twice except for one. Find that single one.

118. Pascal’s TriangleGiven a non-negative integer numRows, generate the first numRows of Pascal’s triangle. Example: In

78. SubsetsGiven a set of distinct integers, nums, return all possible subsets (the power set).Note: The solution set mu

1. Two SumGiven an array of integers, return indices of the two numbers such that they add up to a specific target.You m