static void Main(string[] args)
{
BinaryTree bTree = new BinaryTree("xvbc[#;a#RE##U");
Console.Write("先序遍历:");
bTree.PreOrder(bTree.Head);
Console.WriteLine();
Console.Write("中序遍历:");
bTree.MidOrder(bTree.Head);
Console.WriteLine();
Console.Write("后序遍历：");
bTree.AfterOrder(bTree.Head);
Console.WriteLine();
Console.Write("广度优先遍历：");
bTree.LevelOrder();
Console.ReadKey();
}