LevelOrder.java

import java.util.*;
import java.io.*;

class LevelOrder {
 public static int height(Node root) {
 // Write your code here.
 int height = -1;
 if (root == null) {
 return height;
 }
 int lHeight = 1 + height(root.left);
 int rHeight = 1 + height(root.right);
 if (lHeight > rHeight) {
 return lHeight;
 }
 return rHeight;
 }
 /*
 * 
 * class Node
 * int data;
 * Node left;
 * Node right;
 */
 public static void levelOrder(Node root) {
 int height = height(root);
 for( int level =0; level <= height; level++){
 printLevel(root, level);
 }
 
 }
 

 public static void printLevel(Node node, int level){
 if(node == null){
 return;
 }
 
 if(level == 0){
 System.out.print(node.data);
 System.out.print(" ");
 }else{
 printLevel(node.left, level-1);
 printLevel(node.right, level-1);
 }
 }

 public static Node insert(Node root, int data) {
 if (root == null) {
 return new Node(data);
 } else {
 Node cur;
 if (data <= root.data) {
 cur = insert(root.left, data);
 root.left = cur;
 } else {
 cur = insert(root.right, data);
 root.right = cur;
 }
 return root;
 }
 }

 public static void main(String[] args) {
 Scanner scan = new Scanner(System.in);
 int t = scan.nextInt();
 Node root = null;
 while (t-- > 0) {
 int data = scan.nextInt();
 root = insert(root, data);
 }
 scan.close();
 levelOrder(root);
 }
}