益达的小作坊

参考文章：http://blog.youkuaiyun.com/yutianzuijin/article/details/12887747Given two words (beginWord and endWord), and a dictionary’s word list, find the length of shortest transformation sequence from beginWord

Given a 2D board containing ‘X’ and ‘O’ (the letter O), capture all regions surrounded by ‘X’.A region is captured by flipping all ‘O’s into ‘X’s in that surrounded region.For example, X X X X X O O