Get Level of a node in a Binary Tree

 1 public class DepthOfRandomNode {
 2     public int getDepth(TreeNode root, TreeNode target) {
 3         return helper(root, target, 0);
 4     }
 5     private static int helper(TreeNode root, TreeNode target, int level) {
 6         if (root == null) {
 7             return 0;
 8         }
 9         if (root.val == target.val) {
10             return level + 1;
11         }
12         int left = helper(root.left, target, level + 1);
13         int right = helper(root.right, target, level + 1);
14         if (left != 0) {
15             return left;
16         }else if(right != 0) {
17             return right;
18         }else{
19             return 0;
20         }
21     }
22     public static void main(String[] args) {
23         TreeNode root = new TreeNode(1);
24         TreeNode left1 = new TreeNode(2);
25         TreeNode right1 = new TreeNode(3);
26         TreeNode left21 = new TreeNode(4);
27         TreeNode left22 = new TreeNode(5);
28         TreeNode right21 = new TreeNode(6);
29         TreeNode right22 = new TreeNode(7);
30         root.left = left1;
31         root.right = right1;
32         left1.left = left21;
33         left1.right = right21;
34         right1.left = left22;
35         right1.right = right22;
36         DepthOfRandomNode test = new DepthOfRandomNode();
37         System.out.println(test.getDepth(root,root));
38     }
39 }