function TreeNode(val) {
    this.val = val;
    this.left = this.right = null;
}

var createTree = function(root,data){
    root = new TreeNode(data);
    return root;
}
var arr = [10,5,15,3,7,13,18];

var root = new TreeNode(arr[0]);

var result=[],i=1;
result.push(root);
while(result.length!= 0){
      r= result.shift();
    if(i < arr.length-1){
       // console.log(root)
        result.push(createTree(r.left,arr[i]));
        result.push(createTree(r.right,arr[i+1]));
    }
    //console.log(result);
    i+=2;
}

console.log(root);

想问下这段代码错在哪