Reverse Linked List Recursive

ReverseLinkedListRecursive.java

public class LinkedList
{
  public static ListNode head = null;
  
  public static void main(String[] args)
  {
    head = new ListNode(1);
    
    ListNode curr = head;
    for (int i = 2; i < 6; i++){
     curr.next = new ListNode(i);
     curr = curr.next;
    }
    
    curr = head;
    while (curr != null){
      System.out.println(curr.data);
      curr = curr.next;
    }
    
    curr = recRev(head);
    System.out.println("reversed:");
    while (curr != null){
      System.out.println(curr.data);
      curr = curr.next;
    }
    
   
  }
  
  public static ListNode recRev(ListNode curr){

    if(curr.next == null){
        return curr;
    }
    ListNode head = recRev(curr.next);
    curr.next.next = curr;
    curr.next = null;

    // propogate the head value
    return head;

  }
}
// this will become its own file too (and these can be in any order)
public class ListNode
{
  public int data;
  public ListNode next;
  
  public ListNode(int input)
  {
    data = input;
    next = null;
  }

}

/*output

1
2
3
4
5
reversed:
5
4
3
2
1


*/