摘要：
There is a special square room with mirrors on each of the four walls. Except for the southwest corner, there are receptors on each of the remaining c 阅读全文
摘要：
Given a positive integer N, how many ways can we write it as a sum of consecutive positive integers? Example 1: Example 2: Example 3: Note: 1 <= N <= 阅读全文
摘要：
A rectangle is represented as a list [x1, y1, x2, y2], where (x1, y1) are the coordinates of its bottom-left corner, and (x2, y2) are the coordinates 阅读全文