算法：N叉树的层次遍历算法分享

public List levelorder(Node root) {
		 LinkedList input = new LinkedList<>();
		 LinkedList output = new LinkedList<>();
	        if (root == null) {
	            return output;
	        }

	        input.add(root);
	        while (!input.isEmpty()) {
	            Node node = input.pop();
	            output.add(node.val);
	            if (node.children != null) {
		            for (Node item : node.children) {
		            	input.add(item);
		            }
	            }
	            
	        }
	        return output;
	    }