把二叉树打印成多行

ArrayList<ArrayList<Integer> > Print(TreeNode pRoot) {
        ArrayList<ArrayList<Integer>> arrayList = new ArrayList<>();
        ArrayList<Integer> list = new ArrayList<>();;
        Queue<TreeNode> queue = new LinkedList<>();
        if(pRoot!=null) {
            queue.add(pRoot);
        }
        int nextLevel = 0;
        int count = 1;
        while(!queue.isEmpty()){
                count--;
                TreeNode node = queue.poll();
                list.add(node.val);
                if(node.left!=null){
                    queue.add(node.left);
                    nextLevel++;
                }
                if(node.right!=null){
                    queue.add(node.right);
                    nextLevel++;
                }
                if(count == 0){
                    arrayList.add(list);
                    count = nextLevel;
                    nextLevel = 0;
                    list = new ArrayList<Integer>();
                    
                }
        }
        return arrayList;
    }