import java.util.ArrayList;

public class Graph<E>
{
    ArrayList<Node<E>> adjList;
    public Graph()
    {
	adjList = new ArrayList<>();
    }
    public void addNode(Node<E> n)
    {
	adjList.add(n);
    }
    public static void main(String[] args)
    {
	Graph<Character> g = new Graph<>();
	Node<Character> a = new Node<Character>('a');
	Node<Character> b = new Node<Character>('b');
	Node<Character> c = new Node<Character>('c');
	Node<Character> d = new Node<Character>('d');
	Node<Character> e = new Node<Character>('e');
	g.addNode(a);
	g.addNode(b);
	g.addNode(c);
	g.addNode(d);
	g.addNode(e);
	a.addEdgeTo(b, "aa");
	a.addEdgeTo(c, "bb");
	a.addEdgeTo(d, "gg");
	b.addEdgeTo(c, "cc");
	b.addEdgeTo(a, "dd");
	b.addEdgeTo(d, "ee");
	c.addEdgeTo(e, "ff");
	d.addEdgeTo(e, "hh");
	System.out.println("Reachable from " + a);
	g.reachable(a);
	System.out.println("Reachable from " + a);
	g.reachableNoSelf(a);
	System.out.println("Reachable from " + b);
	g.reachable(b);
	System.out.println("Reachable from " + c);
	g.reachable(c);
	System.out.println("Path from A to E");
	g.findPath1(a,  e);
	System.out.println("Path from A to E");
	g.findPath2(a,  e);
	System.out.println("Done");
    }
    
    
    public void reachable(Node<E> n)
    {
	ArrayList<Node<E>> r = new ArrayList<>();
	iReachable(n, r);
	for (Node<E> nn : r)
	    System.out.println(nn);
    }
    
    private void iReachable(Node<E> n, ArrayList<Node<E>> rble)
    {
	if (rble.contains(n))
	    return;
	rble.add(n);
	for (Edge<E> e : n.getEdges())
	    iReachable(e.getToo(), rble);
    }
    public void reachableNoSelf(Node<E> n)
    {
	ArrayList<Node<E>> r = new ArrayList<>();
	iReachableNoSelf(n, r);
	for (Node<E> nn : r)
	    System.out.println(nn);
    }
    private void iReachableNoSelf(Node<E> n, ArrayList<Node<E>> rble)
    {
	for (Edge<E> e : n.getEdges())
	{
	    if (!rble.contains(e.getToo()))
	    {
		rble.add(e.getToo());
		iReachableNoSelf(e.getToo(), rble);
	    }
	}
    }
    
    public void findPath2(Node<E>from, Node<E> too)
    {
	ArrayList<Node<E>> r = new ArrayList<>();
	Node<E> strt = new Node<>(from.getValue());
	Edge<E> ed = new Edge<>(strt, from, "QQQ");
	ArrayList<Edge<E>> edges = iFindPath2(ed, too, r);
	if (edges==null || edges.size()==0)
	    System.out.println("No path");
	else
	    for (Edge<E> e : edges)
		System.out.println(e);
    }
    
    private ArrayList<Edge<E>> iFindPath2(Edge<E> ee, Node<E> dest, ArrayList<Node<E>> rble)
    {
	if (ee.getToo() == dest) 
	{
	    ArrayList<Edge<E>>  ret = new ArrayList<>();
	    return ret;
	}
	if (rble.contains(ee.getToo()))
	    return null;
	Node<E> n = ee.getToo();
	for (Edge<E> e : n.getEdges())
	{
	    ArrayList <Edge<E>> rtn = iFindPath2(e, dest, rble);
	    if (rtn!=null)
	    {
		rtn.add(e);
		return rtn;
	    }
	}
	return null;
    }
    
    public void findPath1(Node<E>from, Node<E> too)
    {
	ArrayList<Node<E>> r = new ArrayList<>();
	boolean b = iFindPath1(from, too, r);
	if (!b)
	    System.out.println("No Path");
	else
	    System.out.println(from);
    }
    private boolean iFindPath1(Node<E> current, Node<E>dest, ArrayList<Node<E>> rble)
    {
	if (current == dest) 
	    return true;
	if (rble.contains(current))
	    return false;
	rble.add(current);
	for (Edge<E> e : current.getEdges())
	{
	    boolean b = iFindPath1(e.getToo(), dest, rble);
	    if (b)
	    {
		System.out.println(e.getToo());
		return true;
	    }
	}
	return false;
    }
}