130. 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 theboard.
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.lengthn == board[i].length1 <= m, n <= 200board[i][j]is'X'or'O'.
GoogleTopics
Loading editor…
1class Solution:
2 def solve(self, board: List[List[str]]) -> None:
3 """
4 Do not return anything, modify board in-place instead.
5 """
6
Starter codePython 3Spaces: 4
Loading editor…
1class Solution:
2 def solve(self, board: List[List[str]]) -> None:
3 """
4 Do not return anything, modify board in-place instead.
5 """
6
Starter codePython 3Spaces: 4
Examples
Input
[["X","X","X","X"],["X","O","O","X"],["X","X","O","X"],["X","O","X","X"]]
Input
[["X"]]
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