Given the root of a complete binary tree, with root labeled as 1, its left & right children labeld as 2 & 3, and so on and so forth. Question is to find the path of given node index from root. Required time complexity is O(logn).

Example 1:

	    1
	   / \
	 2     3
    / \
   4   5
Given node index 5, path is [1,2,5].

Example 2:

	    1
	   / \
	 2     3
    / \
   4   5
Given node index 6, it does not exist in the tree, so output [].