mediumArrayBreadth First SearchDepth First SearchMatrixUnion Find 0 views

Surrounded Regions

You are given an m x n matrix board containing letters 'X' and 'O', capture regions that are surrounded: To capture a surrounded region, replace all 'O's with 'X's in-place within...

You are given an m x n matrix board containing letters 'X' and 'O', capture regions that are surrounded:

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.

Surrounded Regions diagram

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'.

Hints

No hints yet.

Companies

No companies reported yet.

Discussion

Sign in to join the discussion.

Loading discussion...

Test results

No test cases yet.