摘要： 题目如下： A company has n employees with a unique ID for each employee from 0 to n - 1. The head of the company has is the one with headID. Each employee 阅读全文

摘要： 题目如下： There is a room with n bulbs, numbered from 1 to n, arranged in a row from left to right. Initially, all the bulbs are turned off. At moment k ( 阅读全文

摘要： 题目如下： Given an integer n, return a string with n characters such that each character in such string occurs an odd number of times. The returned string 阅读全文