数据结构中对二叉树的操作,利用递归进行前序,中序,后序,层次遍历.完成根据前序,中序生成二叉树并输出其后序操作.-Binary tree data structure of the operation, prior use of recursive sequence, in order, postorder, level traversal. Completion of the previous order, the order was subsequently generated and output binary sequence operation.