using System;
using System.Collections.Generic;
namespace TreeTest
{
    class Program
    {
        static void Main(string[] args)
        {
            //Build example tree
            Tree tree = new Tree();
            Node a = new Node(2);
            Node b = new Node(7);
            Node c = new Node(2);
            Node d = new Node(6);
            Node e = new Node(5);
            Node f = new Node(11);
            Node g = new Node(5);
            Node h = new Node(9);
            Node i = new Node(4);

            tree.rootNode = a;
            a.Edges.Add(b);
            b.Edges.Add(c);
            b.Edges.Add(d);
            d.Edges.Add(e);
            d.Edges.Add(f);
            a.Edges.Add(g);
            g.Edges.Add(h);
            h.Edges.Add(i);

            //Find node scannin tree from top down
            Node node = tree.FindByValueBreadthFirst(6);
            Console.WriteLine(node != null ? "Found node" : "Did not find node");

            //Find node scanning tree branch for branch.
            node = tree.FindByValueDepthFirst(2);
            Console.WriteLine(node != null ? "Found node" : "Did not find node");

            Console.WriteLine("PRESS ANY KEY TO EXIT");
            Console.ReadKey();
        }
    }
    class Tree
    {
        public Node rootNode;
        public Node FindByValueDepthFirst(int val)
        {
            return rootNode.FindRecursiveDepthFirst(val);
        }
        public Node FindByValueBreadthFirst(int val)
        {
            if (rootNode.Value == val)
                return rootNode;
            else
                return rootNode.FindRecursiveBreadthFirst(val);
        }
    }
    class Node
    {
        public int Value { get; set; }
        public IList<Node> Edges { get; set; }
        public Node(int val)
        {
            Value = val;
            Edges = new List<Node>(2);
        }
        public Node FindRecursiveBreadthFirst(int val)
        {
            foreach (Node node in Edges)
            {
                if (node.Value == val)
                    return node;
            }
            foreach (Node node in Edges)
            {
                Node result = node.FindRecursiveBreadthFirst(val);
                if (result != null)
                    return result;
            }
            return null;
        }
        public Node FindRecursiveDepthFirst(int val)
        {
            if (Value == val)
                return this;
            else
            {
                foreach (Node node in Edges)
                {
                    Node result = node.FindRecursiveDepthFirst(val);
                    if (result != null)
                        return result;
                }
                return null;
            }
        }
    }
}