Print alternate nodes of a linked list using recursion

Given a linked list, print alternate nodes of this linked list.

Examples : 

Input : 1 -> 2 -> 3 -> 4 -> 5 -> 6 -> 7 -> 8 -> 9 -> 10
Output : 1 -> 3 -> 5 -> 7 -> 9 

Input : 10 -> 9
Output : 10

Recursive Approach : 

1. Initialize a static variable(say flag) 
2. If flag is odd print the node 
3. increase head and flag by 1, and recurse for next nodes.

Implementation:

1 3 5 7 9

Time complexity: O(N) where N is no of nodes in linked list
Auxiliary space: O(1), If we consider recursive call stack then it would be O(n)