// CSE 143, Winter 2009, Marty Stepp
// ListNode is a class for storing a single node of a linked list.  This
// node class is for a list of integer values.
// Today's version of the class has a recursive toString method.

public class ListNode {
    public int data;       // data stored in this node
    public ListNode next;  // link to next node in the list

    // post: constructs a node with data 0 and null link
    public ListNode() {
        this(0, null);
    }

    // post: constructs a node with given data and null link
    public ListNode(int data) {
        this(data, null);
    }

    // post: constructs a node with given data and given link
    public ListNode(int data, ListNode next) {
        this.data = data;
        this.next = next;
    }
    
    // Recursively returns a string representation of this node and
    // any other nodes after it, such as "30 -> 20 -> 40".
    public String toString() {
        String result = "" + this.data;
        if (next != null) {
            // there are next node(s) after me
            result += " -> " + next.toString();
        }
        return result;
    }
}