// @Title: N 叉树的层序遍历 (N-ary Tree Level Order Traversal)
// @Author: qisiii
// @Date: 2024-09-14 23:32:36
// @Runtime: 3 ms
// @Memory: 43.8 MB
// @comment: 
// @flag: 
/*
// Definition for a Node.
class Node {
    public int val;
    public List<Node> children;

    public Node() {}

    public Node(int _val) {
        val = _val;
    }

    public Node(int _val, List<Node> _children) {
        val = _val;
        children = _children;
    }
};
*/

class Solution {
    public List<List<Integer>> levelOrder(Node root) {
        List<List<Integer>> result = new ArrayList<>();
        if (root == null) {
            return result;
        }
        Queue<Node> queue = new LinkedList<>();
        queue.offer(root);
        while (!queue.isEmpty()) {
            List<Integer> temp = new ArrayList<>();
            int size = queue.size();
            while (size > 0) {
                Node node = queue.poll();
                temp.add(node.val);
                for(Node child:node.children){
                    if(child!=null){
                        queue.offer(child);
                    }
                }
                size--;
            }
            result.add(temp);
        }
        return result;
    }
}