429N叉树的层序遍历

题目

代码

class Solution {
    public List<List<Integer>> levelOrder(Node root) {
        List<List<Integer>> res = new ArrayList<>();
        Deque<Node> queue = new ArrayDeque<>();   
        if(root == null) return res;
        queue.add(root);
        while(!queue.isEmpty()){
            int size = queue.size();
            List<Integer> path = new ArrayList<>();
            for(int i = 0; i < size; i++){
                Node cur = queue.removeFirst();
                path.add(cur.val);
                for(Node child : cur.children){
                    queue.addLast(child);
                }
            }
            res.add(path);
        }return res;
    }
}

结果