摘要：
题目： The highest building in our city has only one elevator. A request list is made up with N positive numbers. The numbers denote at which floors the 阅读全文
摘要：
题目：At the beginning of every day, the first person who signs in the computer room will unlock the door, and the last one who signs out will lock the d 阅读全文
摘要：
题目：Given a non-negative integer N, your task is to compute the sum of all the digits of N, and output every digit of the sum in English. 给一个非负整数，你的任务是 阅读全文