Given a Binary Tree, convert it into its mirror.
            

Example 1:

Input:
      1
    /  \
   2    3
Output: 2 1 3
Explanation: The tree is
   1    (mirror)  1
 /  \    =>      /  \
3    2          2    3
The inorder of mirror is 2 1 3

Example 2:

Input:
      10
     /  \
    20   30
   /  \
  40  60
Output: 30 10 60 20 40
Explanation: The tree is
      10               10
    /    \  (mirror) /    \
   20    30    =>   30    20
  /  \                   /   \
 40  60                 60   40
The inroder traversal of mirror is
30 10 60 20 40.

Your Task:
Just complete the function mirror() that takes node as paramter  and convert it into its mirror. The printing is done by the driver code only.

Expected Time Complexity: O(N).
Expected Auxiliary Space: O(Height of the Tree).

Constraints:
1 ≤ Number of nodes ≤ 10⁵
1 ≤ Data of a node ≤ 10⁵