Timer is Running

You are given a tree and you need to do the level order traversal on this tree.
Level order traversal of a tree is breadth-first traversal for the tree.

Level order traversal of above tree is 1 2 3 4 5

First line of input contains the number of test cases T. For each test case, there will be only a single line of input which is a string representing the tree as described below: 

  1. The values in the string are in the order of level order traversal of the tree where, numbers denotes node values, and a character “N” denotes NULL child.

  2. For example:

    For the above tree, the string will be: 1 2 3 N N 4 6 N 5 N N 7 N

The function should print the level order traversal of the tree as specified in the problem statement.

Your Task:
You don't have to take any input. Just complete the function levelOrder() that takes the root node as parameter and returns an array containing the level order traversal of the given Binary Tree.

Expected Time Complexity: O(N).
Expected Auxiliary Space: O(N).

1 <= T <= 100
1 <= Number of nodes<= 104
1 <= Data of a node <= 104


1 3 2
10 20 30 40 60 N N
1 3 2
10 20 30 40 60

Testcase1: The tree is
     /      \
   3       2
So, the level order would be 1 3 2
Testcase2: The tree is
                        /        \
                     20         30
                  /       \
               40       60
So, the level order would be 10 20 30 40 60


Note:The Input/Ouput format and Example given are used for system's internal purpose, and should be used by a user for Expected Output only. As it is a function problem, hence a user should not read any input from stdin/console. The task is to complete the function specified, and not to write the full code.

** For More Input/Output Examples Use 'Expected Output' option **

Contributor: Kartik
Author: kartik

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