TREE

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

namespace tree
{
    class BStnode
    {
        public int Data;

        public BStnode left;

        public BStnode right;


        public BStnode(int value)
        {
            Data = value;
            right = left = null;


        }


        public void Printnode()
        {

            Console.WriteLine(Data);
        }


        //insert

        public void insert(int value)
        {
            if (value < Data)
            {
                if (left == null)
                    left = new BStnode(value);

                else
                    left.insert(value);

            } //end if


            else
            {
                if (right == null)
                    right = new BStnode(value);

                else
                    right.insert(value);

            } //end else


        } //end insert







    }

    class Bsttree
    {

      public  BStnode Root;

        public Bsttree()
        {

            Root = null;
        }

        public void insertnode(int value)
        {
            if (Root == null)
                Root = new BStnode(value);

            else
                Root.insert(value);

        }


        public void preorderhelp(BStnode n)
        {

            if (n == null)
                return;


            Console.WriteLine(n.Data);

            preorderhelp(n.left);

            preorderhelp(n.right);



        }//end preorder





        public void inorderhelp(BStnode n)
        {

            if (n == null)
                return;


            inorderhelp (n.left);

            Console.WriteLine(n.Data);



                 inorderhelp(n.right);



        }//end inorder



        public void postrderhelp(BStnode n)
        {

            if (n == null)
                return;


            postrderhelp(n.left);

            postrderhelp(n.right);

            Console.WriteLine(n.Data);


        } //end postorder




        // to print from root in 3 methods





        public void preorder()
        {

            preorderhelp(Root);

        }


        public void inorder()
        {

            inorderhelp(Root);

        }

        public void postorder()
        {

            postrderhelp(Root);

        }

        public BStnode searchhelp(BStnode start, int key)
        {
            if (start == null)
                return null;

            else if (start.Data == key)
                return start;

            else if (start.Data > key)
                return searchhelp(start.left, key);


            else
                return searchhelp(start.right, key);

        }


    }
    class Program
    {
        static void Main(string[] args)
        {

            Bsttree mytree = new Bsttree();
            mytree.insertnode(10);
             mytree.insertnode(11);
             mytree.insertnode(12);
             mytree.insertnode(15);
             mytree.insertnode(19);
             mytree.insertnode(8);
             mytree.insertnode(7);
             mytree.insertnode(5);
             mytree.insertnode(2);
           Console.WriteLine("POST ORDR NLR");
            mytree.postorder();
            Console.WriteLine("_____________________");
            mytree.preorder();
            Console.WriteLine("_________________-");
            mytree.inorder();
            Console.WriteLine("_________________");
            mytree.inorderhelp(mytree.searchhelp(mytree.Root, 8));








            }



        }
    }