private static void Main()
{
var f = new BinaryTree <char>('F');
var b = new BinaryTree <char>('B');
var g = new BinaryTree <char>('G');
var a = new BinaryTree <char>('A');
var d = new BinaryTree <char>('D');
var i = new BinaryTree <char>('I');
var c = new BinaryTree <char>('C');
var e = new BinaryTree <char>('E');
var h = new BinaryTree <char>('H');
f.AddLeft(b);
f.AddRight(g);
b.AddLeft(a);
b.AddRight(d);
g.AddRight(i);
i.AddLeft(h);
d.AddLeft(c);
d.AddRight(e);
Console.WriteLine("PreOrder tree traversal: ");
DisplayTree.PreOrderTraversal(f);
Console.WriteLine();
Console.WriteLine("InOrder tree traversal: ");
DisplayTree.InOrderTraversal(f);
Console.WriteLine();
Console.WriteLine("OutOrder tree traversal: ");
DisplayTree.OutOrderTraversal(f);
Console.WriteLine();
Console.WriteLine("PostOrder tree traversal: ");
DisplayTree.PostOrderTraversal(f);
Console.WriteLine();
Console.WriteLine("LevelOrder tree traversal: ");
DisplayTree.BreadthFirstTreeTraversal(f);
}