摘要：
There are N students in a class. Some of them are friends, while some are not. Their friendship is transitive in nature. For example, if A is a direct 阅读全文
摘要：
Given a 2D array A, each cell is 0 (representing sea) or 1 (representing land) A move consists of walking from one land square 4-directionally to anot 阅读全文