505. The Maze II

class Solution {
    public int shortestDistance(int[][] maze, int[] start, int[] destination)
    {
        // Queue<int[]> q = new PriorityQueue<>((a, b)->(a[2] - b[2]));
        Queue<int[]> q = new LinkedList<>();
        q.offer(new int[]{start[0], start[1], 0});
        int m = maze.length, n = maze[0].length;
        int[][] visited = new int[m][n];
        for(int[] v : visited) Arrays.fill(v, 10001);
        int[] dx = {0, 1, 0, -1}, dy = {1, 0, -1, 0};
        while(!q.isEmpty())
        {
            int[] p = q.poll();
            int i = p[0], j = p[1], step = p[2];
            // if(i == destination[0] && j == destination[1]) return step;
            if(visited[i][j] <= step) continue;
            visited[i][j] = step;
            for(int k = 0; k < 4; k++)
            {
                int ni = i, nj = j;
                while(ni >= 0 && ni < m && nj >= 0 && nj < n && maze[ni][nj] == 0)
                {
                    ni += dx[k];
                    nj += dy[k];
                }
                ni -= dx[k];
                nj -= dy[k];
                int nstep = step + Math.abs(ni - i) + Math.abs(nj - j);
                q.offer(new int[]{ni, nj, nstep});
            }
        }
        // return -1;
        return visited[destination[0]][destination[1]] == 10001 ? -1 : visited[destination[0]][destination[1]];
    }
}