[Hackerrank] TreePostorderTraversal

www.hackerrank.com/challenges/tree-postorder-traversal/problem

Tree: Postorder Traversal | HackerRank

package exam.complete;
//https://www.hackerrank.com/challenges/tree-postorder-traversal/problem

import exam.Node;

public class TreePostorderTraversal {
    public static void main(String[] args) {
        Node node4 = new Node(4);
        Node node3 = new Node(3, null, node4);
        Node node6 = new Node(6);
        Node node5 = new Node(5, node3, node6);
        Node node2 = new Node(2, null, node5);
        Node node1 = new Node(1, null, node2);
        postOrder(node1);
    }
    public static void postOrder(Node root) {
        if(root.left != null) postOrder(root.left);
        if(root.right != null) postOrder(root.right);
        System.out.print(root.val+" ");
    }
}