13. Shortest Path in Binary Matrix

class Solution {
    public int shortestPathBinaryMatrix(int[][] grid) {
        if(grid[0][0] == 1) return -1;
        int m = grid.length;
        int n = grid[0].length;
        
        Queue<int[]> q = new LinkedList<>();
        q.add(new int[]{0,0,1});
        grid[0][0] =1;
        
        int[][] dir = {{0, 1}, {1, 0}, {0, -1}, {-1, 0}, {1, 1}, {1, -1}, {-1, 1}, {-1, -1}};
        while(!q.isEmpty()) {
            int size = q.size();
            while(size-- > 0) {
                int[] point = q.poll();
                
                if(point[0] ==  m-1 && point[1] == n-1)
                    return point[2];
                
                for(int[] d : dir) {
                    int r = point[0] + d[0];
                    int c = point[1] + d[1];
                    
                    if(r >= 0 && c >= 0 && r < m && c < n && grid[r][c] == 0){
                        q.add(new int[]{r, c, point[2]+1});
                        grid[r][c] = 1;
                    }
                }
            }
        }
        
        return -1;
    }
}