function BST(){
 this.root = null
 this.insert = insert
 this.find = find
 this.mirror = mirror;
 
 }
 function Node(data,left,right){
 this.data = data
 this.left = left
 this.right = right
 this.show = show
 }
 function show() {
 return this.data;
 }
 function mirror(root){
 if(root == null){
 return
 }
 if(root.left == null && root.right == null){
 return
 }
 let temp = root.left;
 root.left = root.right;
 root.right = temp;
 mirror(root.left)
 mirror(root.right)
 }
 function insert(data){
 var n = new Node(data,null,null)
 if(this.root == null){
 this.root = n
 }else{
 var current = this.root
 while(true){
 if(data < current.data){
 if(current.left == null){
 current.left = n
 break
 }
 current = current.left
 }else{
 if(current.right == null){
 current.right = n
 break
 }
 current = current.right
 }
 }
 }
 }
 function find(data){
 var current = this.root
 while(true){
 if(data == current.data){
 return current
 }
 current = data < current.data ? current.left : current.right
 if(current == null){
 return null
 }
 }
 }
 function inorder(node){
 if(!(node == null)){
 inorder(node.left)
 console.log(node.show())
 inorder(node.right)
 }
 }
 var nums = new BST()
 nums.insert(23)
 nums.insert(22)
 nums.insert(16)
 nums.insert(5)
 nums.insert(3)
 nums.insert(99)
 nums.insert(22)
 inorder(nums.root) 
 mirror(nums.root)
 console.log(nums.root)

很简单的 看就完了。