1162 As Far from Land as Possible

Question

My Solution

class Solution {
    public int maxDistance(int[][] grid) {
        Queue<int[]> queue = new LinkedList<>();
        int[][] directions = new int[][] {{1,0},{-1,0},{0,1},{0,-1}};
        int m = grid.length;
        int n = grid[0].length;
        int max = Integer.MIN_VALUE;
        
        for(int i=0; i<m; i++){
            for(int j=0; j<n; j++){
                if(grid[i][j] == 1){
                    grid[i][j] = 0;
                    queue.add(new int[]{i,j}); // add land to queue
                }else{
                    grid[i][j] = Integer.MIN_VALUE;
                }
            }
        }
        
        
        while(!queue.isEmpty()){
            int[] pos = queue.poll();
            for(int[] dir: directions){
                int x = pos[0] + dir[0];
                int y = pos[1] + dir[1];
                if( x >= 0
                  && y >= 0
                  && x < m
                  && y < n
                  && grid[x][y] < 0){
                    queue.add(new int[]{x,y});
                    grid[x][y] = grid[pos[0]][pos[1]] + 1;
                    max = Math.max(max, grid[x][y]);   
                }
            }
        }
        
        return max == Integer.MIN_VALUE ? -1: max;
    }
}