Question

I have two classes, ListNode and MyList.

ListNode:

public class ListNode {
    private String str;
    private ListNode next;
    public ListNode(String str) {
        this.str = str;
        next = null;
    }
    public String getString() {
        return str;
    }
    public ListNode getNext() {
        return next;
    }
    public void setNext(ListNode next) {
        this.next = next;
    }
}

MyList

public MyList RecReverse() { //my attempt at the recursive method
    if (head.getNext() == null) {
        return this;
    }
    MyList remainder = new MyList();
    remainder.head = head.getNext(); //start rest of list at the 2nd thing
    ListNode temp = new ListNode(head.getString()); //get the first thing in list
    temp.setNext(null); //set to null to indicate end of list

    remainder.RecReverse(); //reverse the remaining things in the list
    remainder.head.setNext(temp); //then add it to the end of the reversed list

    return remainder;



}

So as you can see the MyList class has a ListNode variable which we need to use. It is required that the RecReverse method take no arguments and return a MyList object. The method must also use the function Rev(L) = Rev(L`).x, where L` is the remainder of the list and x is the first thing in the list.

Currently when I reverse the list and print it it only prints the following:

two

one

in the console

Answer 1

public MyList RecReverse() { //my attempt at the recursive method
    if (head.getNext() == null) {
        return this;
    }

    MyList remainder = new MyList();
    remainder.head = head.getNext(); // New list has rest of this list (after head)
    ListNode temp = new ListNode(head.getString()); // save the first thing in list

    remainder = remainder.RecReverse(); //reverse the things in the new 2nd part list

    remainder.end().setNext(temp); // put old head on the end

    return remainder;

}

private ListNode end() {
    ListNode curr = head;
    while (curr.getNext() != null) {
        curr = curr.getNext();
    }
    return curr;
}