/* This is really a linked list class for a linked list of Strings.
 * No loops allowed in these parts!
 */
public class Recursion {
 
  // Class for the links in the linked list.
  // No getters and setters necessary because the fields are public.
  private class Node {
    public String data;
    public Node next;
 
    public Node(String data) {
      this.data = data;
      next = null;
    }
 
    public Node(String data, Node next) {
      this.data = data;
      this.next = next;
    }
  }
 
  // Pointer to the first Node
  private Node first;
 
  public Recursion() {
    first = null;
  }
 
  // Builds a linked list from the given array.
  // I've written this one for you - you're welcome!
  // Feel free to use it for your own debugging.
  public void build(String[] contents) {
    first = buildHelper(contents, 0);
  }
 
  // (No need to change this method.)
  private Node buildHelper(String[] contents, int index) {
    if (index >= contents.length) {
      return null;
    }
    else {
      return new Node(conents[index], buildHelper(contents, index+1));
    }
  }
 
  // Prints the list in order.
  // We did this in class!
  public void print() {
    printHelper(first);
  }
 
  // (No need to change this method.)
  private void printHelper(Node cur) {
    if (cur != null) {
      System.out.println(cur.data);
      printHelper(cur.next);
    }
  }
      
 
  // Inserts a new element into the second position
  // (i.e., index 1).
  public void addSecond(String element) {
  }
 
  // Prints the list in reverse order, last node first.
  // I've started a helper method for you below.
  public void printInReverseOrder() {
  }
 
  private void printReverseHelper(Node cur) {
  }
 
  // Gets the longest word in the list.
  // If more than one word is tied for the longest,
  // you should return the FIRST one.
  public String longest() {
    return null; // Change this line!!!
  }
 
  // Helper method
  private String longestHelper(Node cur) {
    return null; // Change this line!!!
  }
 
  // Gets the contents of the i-th node, counting from 0.
  // Remember you have to write this recursively.
  // Would you like to add a helper method???
  public String get(int index) throws IndexOutOfBoundsException {
    return null; // Change this line!!!
  }
 
  // Duplicates every element, so like
  // ["a" "b" "c"] would become
  // ["a" "a" "b" "b" "c" "c"]
  // A helper method would be lovely, wouldn't it?
  public void duplicate() {
  }
 
  // Removes all occurrences of the given string
  // Don't forget your helper method!
  public void remove(String rem) {
  }
 
}