任务： 　　要求能够输入树的各个结点，并能够输出用不同方法遍历的遍历序列；分别建立建立二叉树存储结构的的输入函数、输出层序遍历序列的函数、输出先序遍历序列的函数； -Whereas it is essential, if man is not to be compelled to have recourse, as a last resort, to rebellion against tyranny and oppressi