How to segregate a linked list into two other lists, one with odd indices the other one with even indices but in recursion way

Question

The question asked to write a function that can split a linked list into two other lists, one with odd indices the other one with even indices but recursively. I have read all the similar questions in stack overflow, but they did not have recursive way.

Here is my try:

public class LinkedList {
Node head;
static int count = 0;
static LinkedList oddList = new LinkedList();
static LinkedList evenList = new LinkedList();

static class Node {
    int data;
    Node next;

    Node(int d) {
        data = d;
        next = null;
    }
}

public static void split(Node head) {

    if (head == null) return;
    split(head.next);
    if ((++count) % 2 == 0) {
        insert(evenList, head.data);
    } else
        insert(oddList, head.data);
}

This program just do the traverse recursively not the inserting, I do not know how to traverse and insert elements in my two linked list all in recursion .

Could you help me write that function to do that work.?

Answer 1

Pseudocode:

TwoLists splitEvenAndOddIndices(List originalList) {
    if (originalList.isEmpty()) {
        return two empty lists;
    }
    Element head = remove the head (the frontmost element) from originalList;
    TwoLists result = splitEvenAndOddIndices(originalList);
    Swap the two lists in result;
    Prepend head to the first list in result,
    return result;
}