Surrounded Regions

You are given an `m x n` matrix `board` containing **letters** `'X'` and `'O'`, **capture regions** that are **surrounded**: - **Connect**: A cell is connected to adjacent cells horizontally or vertically. - **Region**: To form a region **connect every** `'O'` cell. - **Surround**: The region is surrounded with `'X'` cells if you can **connect the region **with `'X'` cells and none of the region cells are on the edge of the `board`. To capture a **surrounded region**, replace all `'O'`s with `'X'`s **in-place** within the original board. You do not need to return anything.   **Example 1:** **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:** In the above diagram, the bottom region is not captured because it is on the edge of the board and cannot be surrounded. **Example 2:** **Input:** board = [["X"]] **Output:** [["X"]]   **Constraints:** - `m == board.length` - `n == board[i].length` - `1 <= m, n <= 200` - `board[i][j]` is `'X'` or `'O'`.