Get Watched Videos by Your Friends LeetCode solution in Java

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class Solution {
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  public List<String> watchedVideosByFriends(
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      List<List<String>> watchedVideos, int[][] friends, int id, int level) {
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    int n = friends.length;
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    boolean[] visited = new boolean[n];
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    List<List<Integer>> graph = new ArrayList<>();
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    for (int i = 0; i < n; i++) graph.add(new ArrayList<>());
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    for (int i = 0; i < n; i++) {
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      for (int j = 0; j < friends[i].length; j++) {
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        graph.get(i).add(friends[i][j]);
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      }
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    }
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    // System.out.println(graph.get(0));
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    Queue<Integer> queue = new ArrayDeque<>();
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    queue.offer(id);
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    visited[id] = true;
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    Map<String, Integer> answer = new HashMap<>();
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    while (!queue.isEmpty() && level > 0) {
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      int size = queue.size();
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      for (int i = 0; i < size; i++) {
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        int vertex = queue.remove();
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        for (int child : graph.get(vertex)) {
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          if (!visited[child]) {
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            //   if(level == 1) System.out.println(watchedVideos.get(child));
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            if (level == 1) {
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              for (String a : watchedVideos.get(child)) {
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                answer.put(a, answer.getOrDefault(a, 0) + 1);
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              }
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            }
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            visited[child] = true;
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            queue.offer(child);
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          }
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        }
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      }
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      level--;
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    }
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    Queue<String[]> sortedQueue =
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        new PriorityQueue<>(
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            (a, b) -> {
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              if (a[1].equals(b[1])) return a[0].compareTo(b[0]);
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              return Integer.parseInt(a[1]) - Integer.parseInt(b[1]);
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            });
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    for (String key : answer.keySet()) {
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      sortedQueue.offer(new String[] {key, Integer.toString(answer.get(key))});
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    }
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    List<String> finalAnswer = new ArrayList<>();
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    while (!sortedQueue.isEmpty()) finalAnswer.add(sortedQueue.remove()[0]);
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    return finalAnswer;
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  }
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}