js创建二叉树

二叉树创建规则：从上到下一层一层的，按照从左到右的顺序进行构造
输入"10,5,12,4,7"值，构造的树如下：

        function Node(data,left,right){
            this.data = data;
            this.left = left;
            this.right = right;
        }
        function BST(){
            this.root = null;
        }
        BST.prototype.insert = function(data){
            var node = new Node(data,null,null);
            if(this.root == null){
                this.root = node;
            }else{
                var current = this.root;
                var parent;
                while(true){
                    parent = current;
                    if(data < current.data){
                        current = current.left;
                        if(current == null){
                            parent.left = node;
                            break;
                        }
                    }else{
                        current = current.right;
                        if(current == null){
                            parent.right = node;
                            break;
                        }
                    }
                }
            }
        }





        function fn(arr){
            var bst  = new BST();
            for(var i = 0;i<arr.length;i++){
                bst.insert(arr[i])
            }
            console.log(bst.root)
        }

        fn([12,8,11,15,18,7,16,6])