TLE bài "Most popular friend" trên codechef?

[Safety_For (Pioneer)]

Most Popular Friend - Problems | CodeChef

   public class Main {
    	static final PrintWriter pw = 
    			new PrintWriter(new OutputStreamWriter(System.out), true);
    	static final FastReader reader = new FastReader();
    	
    	public static void main(String[] args){
    		int num = reader.nextInt();
    		
    		for(int i=0;i<num;i++) {
    			int n = reader.nextInt();
    			
    			List<List<Integer>> list = new ArrayList<>();
    			
    			for(int j=0;j<n;j++) {
    				String input = reader.nextLine();
    				list.add(new ArrayList<>());
    				
    				for(int data : split(input)) {
    					list.get(j).add(data - 1);
    				}
    			}
    			
    			long min = Long.MAX_VALUE;
    			int id = -1;
    			
    			for(int j=0;j<n;j++) {
    				long totalDist = 0;
    				HashSet<Integer> visited = new HashSet<>();
    				Queue<BfsObj> q = new LinkedList<>();
    				
    				q.add(new BfsObj(j, 0));
    				visited.add(j); // visited j
    				while(!q.isEmpty()) {
    					BfsObj curr = q.peek();
    					q.remove();
    					
    					for(int next : list.get(curr.id)) {
    						if(!visited.contains(next)) {
    							q.add(new BfsObj(next, curr.dist + 1));
    							visited.add(next);
    							totalDist += (curr.dist + 1);
    						}
    					}
    				}
    				
    				if(min > totalDist) {
    					min = totalDist;
    					id = j;
    				}
    			}
    			
    			System.out.println((id + 1) + " " + String.format("%.6f", 
    					((double)min / n)));
    		}
    	}
    	
    	public static int[] split(String input) {
    		String[] data = input.split(" ");
    		
    		int[] list = new int[data.length];
    		for(int i=0;i<data.length;i++) {
    			list[i] = Integer.parseInt(data[i]);
    		}
    		
    		return list;
    	}
    }

    class BfsObj{
    	public final int id;
    	public final int dist;
    	
    	public BfsObj(int id, int dist) {
    		this.id = id;
    		this.dist = dist;
    	}
    }

Có cách nào cải thiện bfs của em không ạ? Hay bfs của em bị sai ở đâu? Hệ thống chấm TLE 0.5s.