创建二叉树，并实现二叉树前序、中序递归遍历算法和二叉树的后序非递归遍历-create binary tree, and to achieve binary tree before the sequence, sequence recursive traversal of a binary tree algorithm and after non - recursive traversal sequence

创建二叉树，并实现二叉树前序、中序递归遍历算法和二叉树的后序非递归遍历-create binary tree, and to achieve binary tree before the sequence, sequence recursive traversal of a binary tree algorithm and after non- recursive traversal sequence