Reverse alternate groups of K nodes in a Singly Linked List

We are given a pointer to the head of a singly Linked List and you have to write a function to reverse the elements of the given singly Linked List in alternate groups of K nodes. Once the operation is performed, pointer to the head of the Linked List must be returned from the function.

Input: 1 -> 2 -> 3 -> 4 -> 5 -> 6 -> 7 -> 8 -> 9 -> 10
and
k = 3

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

In the above example, k is equal to 3. Therefore we are required to reverse the elemen...