package LeetCode;

import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.Queue;

public class LC_429 {
    public List<List<Integer>> levelOrder(Node root) {
        List<List<Integer>> res = new ArrayList<>();
        if (root == null) return res;
        Queue<Node> que = new LinkedList<>();
        que.add(root);
        while (!que.isEmpty()) {
            List<Integer> res_tmp = new ArrayList<>();
            int len = que.size();
            while (len > 0) {
                Node cur = que.poll();
                que.addAll(cur.children);
                res_tmp.add(cur.val);
                len--;
            }
            res.add(res_tmp);
        }
        return res;
    }
}