static void Main(string[] args) { Tree tree = new Tree(); //实例化二叉树 string Input = Console.ReadLine(); Input = new Regex("[\r\n ]").Replace(Input, ""); //判断输入数据是否合法 if (new Regex("[^A-Za-z#]").IsMatch(Input)) { Console.WriteLine("Error input"); } else { tree.RecursiveCreate(Input); //递归构建二叉树 tree.RecursivePreOrderTraversal(); //递归前序遍历 Console.WriteLine(); tree.RecursiveInvert(); //递归反转二叉树 tree.NonRecursivePreOrderTraversal(); //非递归后序遍历 Console.ReadLine(); } }