package cse1030;


public class LinkedList<E> {

  private static class Node<E> {
    private E data;
    private Node<E> next;
    
    public Node(E data) {
      this.data = data;
      this.next = null;
    }
  }
  
  private Node<E> head;
  
  public LinkedList() {
    this.head = null;
  }
  
  public void add(E element) {
    if (this.head == null) {
      this.head = new Node<E>(element);
    }
    else {
      add(element, this.head);
    }
  }
  
  private static <E> void add(E element, Node<E> n) {
    if (n.next == null) {
      n.next = new Node<E>(element);
    }
    else {
      add(element, n.next);
    }
  }
  
  @Override
  public String toString() {
    StringBuilder b = new StringBuilder();
    b.append("[");
    Node<E> n = this.head;
    while (n != null) {
      b.append(n.data);
      if (n.next != null) {
        b.append(", ");
      }
      n = n.next;
    }
    b.append("]");
    return b.toString();
  }
  
  public int size() {
    return LinkedList.size(this.head);
  }
  
  private static <E> int size(Node<E> n) {
    if (n == null) {
      return 0;
    }
    return 1 + LinkedList.size(n.next);
  }
  
  
  public static void main(String[] args) {
    LinkedList<String> t = new LinkedList<String>();
    System.out.println(t.size() + ": " + t);
    
    t.add("hello");
    System.out.println(t.size() + ": " + t);
    
    t.add("goodbye");
    System.out.println(t.size() + ": " + t);
  }
}