层序遍历

层序遍历：A -> B -> C -> D -> E -> F -> G -> H -> I

层序遍历 #

  public static void level(Node head) {
    if (head == null)
      return;
    Queue<Node> queue = new LinkedList<>();
    queue.add(head);
    while (!queue.isEmpty()) {
      Node cur = queue.poll();
      System.out.print(cur.value + " ");
      if (cur.left != null)
        queue.add(cur.left);
      if (cur.right != null)
        queue.add(cur.right);
    }
  }