import java.util.*; class Program { public static int nodeDepths(BinaryTree root) { // Write your code here. return findNodeSum(root, 0); } public static int findNodeSum(BinaryTree root, int depth){ int sum = 0; if (root == null){ return 0; } sum += depth; sum += findNodeSum(root.left, depth + 1); sum += findNodeSum(root.right, depth + 1); return sum; } static class BinaryTree { int value; Binar..