Example: N‐Ary Levelorder Traversal - rFronteddu/general_wiki GitHub Wiki

class Solution {
    public List<List<Integer>> levelOrder(Node root) {
        List<List<Integer>> result = new ArrayList<>();
        if (root == null) {
            return result;
        }
        
        Queue<Node> q = new LinkedList<>();
        q.add(root);
        int size = 1;
        
        while (!q.isEmpty()) {
            List<Integer> currResult = new ArrayList<>();
            int currentSize = q.size();
            for (int i = 0; i < currentSize; i++) {
                var curr = q.poll();
                currResult.add (curr.val);
                for (var c : curr.children) {
                    q.add(c);     
                } 
            }
            result.add(currResult);
        } 
        return result;
    }  
}