657. Robot Return to OriginThere is a robot starting at position (0, 0), the origin, on a 2D plane. Given a sequence of

627. Swap SalarySQL架构 create table if not exists salary(id int, name varchar(100), sex char(1), salary int) Truncate tab

620. Not Boring MoviesSQL架构 Create table If Not Exists cinema (id int, movie varchar(255), description varchar(255), rat

595. Big CountriesSQL架构 Create table If Not Exists World (name varchar(255), continent varchar(255), area int, populatio

561. Array Partition IGiven an array of 2n integers, your task is to group these integers into n pairs of integer, say (

509. Fibonacci NumberThe Fibonacci numbers, commonly denoted F(n) form a sequence, called the Fibonacci sequence, such t

476. Number ComplementGiven a positive integer, output its complement number. The complement strategy is to flip the bit

461. Hamming DistanceThe Hamming distance between two integers is the number of positions at which the corresponding bit

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