1 //an order arr to binary search tree
 2 (function(){
 3   function main(arr){
 4       var node  = {};
 5       if(arr.length <= 1)
 6         return {data:arr[0]};
 7       var flag = Math.floor(arr.length/2);
 8       node.data =http://www.mamicode.com/ arr[flag];
 9       var leftArr = arr.slice(0,flag);
10       var rightArr = arr.slice(flag+1);
11       node.leftSubTree = main(leftArr);
12       node.rightSubTree = main(rightArr);
13       return node;
14   }
15   var _arr = [1,2,3,4,5,6,7,8,9];
16   console.log(main(_arr));
17 })()