Binary tree

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

namespace DataStructure
{
    namespace Tree
    {
        internal class BinaryTree
        {
            private Node root;
            public void Insert(int data)
            {
                var node = new Node(data);
                if (root == null)
                {
                    root = node;
                    return;
                }

                var current = root;

                while (true)
                {
                    if (current.data > data)
                    {
                        if (current.leftChild == null)
                        {
                            current.leftChild = node;
                            break;
                        }
                        current = current.leftChild;
                    }
                    else if (current.data < data)
                    {
                        if (current.rightChild == null)
                        {
                            current.rightChild = node;
                            break;
                        }
                        current = current.rightChild;
                    }
                }
            }
            public void InOrder()
            {
                InOrder(root);
            }
            public void PreOrder()
            {
                InOrder(root);
            }
            public void PostOrder()
            {
                InOrder(root);
            }
            private void InOrder(Node node)
            {
                if (node == null)
                    return;
                InOrder(node.leftChild);
                Console.Write(node.data);
                InOrder(node.rightChild);
            }
            private void PreOrder(Node node)
            {
                if (node == null)
                    return;
                Console.Write(node.data);
                PreOrder(node.leftChild);
                PreOrder(node.rightChild);
            }
            private void PostOrder(Node node)
            {
                if (node == null)
                    return;
                PostOrder(node.leftChild);
                PostOrder(node.rightChild);
                Console.Write(node.data);
            }

            public int Height()
            {
                return Height(root);
            }
            private int Height(Node node)
            {
                if (node == null)
                {
                    return -1;
                }
                if (IsLeaf(node))
                {
                    return 0;
                }
                return 1 + Math.Max(Height(node.leftChild), Height(node.rightChild));
            }
            private bool IsLeaf(Node node)
            {
                if (node.leftChild == null && node.rightChild == null)
                {
                    return true;
                }
                return false;
            }

            public bool IsEqual(Node first, Node second)
            {
                if (first == null && second == null)
                    return true;
                if (first != null && second != null)
                {
                    return first.data == second.data &&
                        IsEqual(first.rightChild, second.rightChild) &&
                        IsEqual(first.leftChild, second.leftChild);
                }
                return false;
            }
        }
        public class Node
        {
            public int data;
            public Node leftChild;
            public Node rightChild;
            public Node(int data)
            {
                this.data = data;
            }
        }
    }
}