Tag: Surrounded Regions

Given an m x n matrix board containing 'X' and 'O', capture all regions surrounded by 'X'. A region is captured by flipping all 'O's into 'X's in that surrounded region. Example: Input: board = [ ["X","X","X","X"], ["X","O","O","X"], ["X","X","O","X"], ["X","O","X","X"] ] Output: [ ["X","X","X","X"], ["X","X","X","X"], ["X","X","X","X"], ["X","O","X","X"] ] Explanation: Surrounded…