Given a Binary Tree of N edges. The task is to convert this to a Circular Doubly Linked List(CDLL) in-place. The left and right pointers in nodes are to be used as previous and next pointers respectively in converted CDLL. The order of nodes in CDLL must be same as Inorder of the given Binary Tree. The first node of Inorder traversal (left most node in BT) must be head node of the CDLL.

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

For each test case, in a new line, print the traversals of CDLL.

Your Task:
You don't have to take input. Complete the function bTreeToCList() that takes root as a parameter and returns the head of the list. The printing is done by the driver code.

1 <= T <= 30
1 <= N <= 104
1 <= Data of a node <= 105


1 3 2
10 20 30 40 60
3 1 2 
2 1 3
40 20 60 10 30 
30 10 60 20 40
Testcase 1:
After converting tree to CDLL, when CDLL is is traversed from head to tail and then tail to head, elements are displayed as in the output.


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: Saksham Raj Seth
Author: saksham seth

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