✅Java Solution||0ms||100% faster||Easy||Beginner Friendly🔥
If you really found my solution helpful please upvote it, as it motivates me to post such kind of codes and help the coding community, if you have some queries 
**If you really found my solution helpful please upvote it, as it motivates me to post such kind of codes and help the coding community, if you have some queries or some improvements please feel free to comment and share your views.**\n```\nclass Solution {\n    ArrayList<Integer> al = new ArrayList<>();\n    public List<Integer> postorder(Node root) {\n        postOrder(root);\n        return al;\n    }\n    public void postOrder(Node node){\n        if(node == null){\n            return;\n        }\n        for(Node n : node.children){\n            postOrder(n);\n        }\n        al.add(node.val);\n    }\n}\n```\n**Happy coding**
['Recursion', 'Java']