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• 0130. Surrounded Regions
  • Approach
  • Python
  • C++

TODO 0130. Surrounded Regions   medium

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: A region is surrounded if none of the 'O' cells in that region are on the edge of the board. Such regions are *completely enclosed *by 'X' cells.

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'.

TODO Approach

Write your approach here.

TODO Python

class Solution:
    def solve(self, board: List[List[str]]) -> None:
        """
        Do not return anything, modify board in-place instead.
        """

TODO C++

class Solution {
public:
    void solve(vector<vector<char>>& board) {
        
    }
};