From a null binary tree, insert key values successively according to the insertion algorithm of a binary search tree strictly (no rotation and balance) to construct a binary search tree. What is the insertion sequence that could make the tree have a smallest depth with a key value set { 14,32,47,6,9,12,78,63,29,81 }? Please write down the elements successively, and there is one blank space between two elements. If there are more than one answer that meet the condition, please make the element which needs to be inserted first as small as possible in your answer. 从空二叉树开始,严格按照二叉搜索树的插入算法(不进行旋转平衡),逐个插入关键码构造出一棵二叉树,以怎样的顺序插入关键码集合 {14 , 32 , 47 , 6 , 9 , 12 , 78 , 63 , 29 , 81} 可以使得树的深度最小? 请依次写出插入到树中的元素,每两个元素之间用一个空格隔开。 如果有多组满足要求的方案,请使得你的答案中先插入的元素尽可能的小。