Tree

using System;
using System.Collections.Generic;
using System.Text;

namespace Test
{
    public class TNode
    {
        public TNode Left;
        public TNode Right;
        public int data;
    }

    public class Tree
    {
        public TNode Root;

        public void PreOrder(TNode node)
        {
            if (node == null)
                return;

            /* first print data of node */
            Console.Write(node.data + " ");

            /* then recur on left sutree */
            PreOrder(node.Left);

            /* now recur on right subtree */
            PreOrder(node.Right);
        }

        public void InOrder(TNode node)
        {
            if (node == null)
                return;

            /* first recur on left child */
            InOrder(node.Left);

            /* then print the data of node */
            Console.Write(node.data + " ");

            /* now recur on right child */
            InOrder(node.Right);
        }

        public void PostOrder(TNode node)
        {
            if (node == null)
                return;

            // first recur on left subtree
            PostOrder(node.Left);

            // then recur on right subtree
            PostOrder(node.Right);

            // now deal with the node
            Console.Write(node.data + " ");
        }

        public void AddNode(int item)
        {
            if (Root == null)
            {
                this.Root = new TNode();
                this.Root.data = item;
            }
            else
            {
                var a = Root.data;
                TNode curr = Root;
                while (a != 0)
                {
                    if (curr.data > item)
                    {
                        if (curr.Left == null)
                        {
                            curr.Left = new TNode();
                            curr.Left.data = item;
                            a = 0;
                        }
                        else
                        {
                            curr = curr.Left;
                        }
                    }

                    if (curr.data < item)
                    {
                        if (curr.Right == null)
                        {
                            curr.Right = new TNode();
                            curr.Right.data = item;
                            a = 0;
                        }
                        else
                        {
                            curr = curr.Right;
                        }
                    }
                }
            }
        }
    }
}