摘要：
Given a List of words, return the words that can be typed using letters of alphabet on only one row's of American keyboard like the image below. Examp 阅读全文
摘要：
Given an integer, return its base 7 string representation. Example 1: Example 2: Note: The input will be in range of [-1e7, 1e7]. 这道题给了我们一个数，让我们转为七进制的 阅读全文
