摘要：
Given a positive integer, check whether it has alternating bits: namely, if two adjacent bits will always have different values. Example 1: Input: 5 O 阅读全文
摘要：
Given a non-empty 2D array grid of 0's and 1's, an island is a group of 1's (representing land) connected 4-directionally (horizontal or vertical.) Yo 阅读全文
摘要：
You are given a data structure of employee information, which includes the employee's unique id, his importance value and his directsubordinates' id. 阅读全文