529. Minesweeper

class Solution {
    private int[][] dirs = {{0, 1}, {0, -1}, {1, 0}, {-1, 0}, {-1, -1}, {1, 1}, {1, -1}, {-1, 1}};
    public char[][] updateBoard(char[][] board, int[] click) {
        int row = click[0], col = click[1];
        int m = board.length, n = board[0].length;
        
        if (board[row][col] == 'M' || board[row][col] == 'X') {
            board[row][col] = 'X';
            return board;
        }
        
        int num = 0;
        for (int[] dir : dirs) {
            int newRow = dir[0] + row;
            int newCol = dir[1] + col;
            
            if (newRow >= 0 && newRow < m && 
               newCol >= 0 && newCol < n && 
               board[newRow][newCol] == 'M') {
                num++;
            }
        }
        
        if (num > 0) {
            board[row][col] = (char) (num + '0');
            return board;
        }
        
        board[row][col] = 'B';
        for (int[] dir : dirs) {
            int newRow = dir[0] + row;
            int newCol = dir[1] + col;
            
            if (newRow >= 0 && newRow < m && 
               newCol >= 0 && newCol < n && 
               board[newRow][newCol] == 'E') {
                updateBoard(board, new int[]{newRow, newCol});
            }
        }
        
        return board;
    }
}