dsa · medium
Surrounded Regions
GreyOrangeGraphRecursion
Board of "X" / "O". Capture ("O"→"X") every region fully surrounded by "X". Border-connected "O"s stay. Return the board.
Arguments
board— the 2D board
**Example**
`` Input: [["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"]] ``
Constraints
1 <= m, n <= 200 Hidden tests include near-max size for this bound; a slower-than-intended solution TLEs.
Examples
Example 1
Input: [["X","X","X","X"],["X","O","O","X"],["X","X","O","X"],["X","O","X","X"]] Expected: [["X","X","X","X"],["X","X","X","X"],["X","X","X","X"],["X","O","X","X"]]