Binary Search Tree

Assume the following definition for a node of a binary tree. public class Node { public int data; public Node left; public Node right; public Node (int d) { data = d; left = null; right = null; } Write a recursive function sum (Node root) which calculates and returns the sum of the data values in all the nodes of the binary tree rooted at the given root node. public static int sum (Node root) { Consider the following recursive function: public static void fun (int a, int b, int c) { int d = 3 - (b + c); if(a > 1) Fun (a-1, b, d); System.out.println(a + " " + b + if(a > 1) fun (a-1, d, c); + c) What is the output generated by calling fun (3, 2, 1)