//Given an array where elements are sorted in ascending order, convert it to a height balanced BST.
/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode(int x) { val = x; }
* }
*/
public class Solution {
public TreeNode sortedArrayToBST(int[] nums) {
if(nums.length==0) return null;
return constructBST(nums,0,nums.length-1);
}
public TreeNode constructBST(int[] nums,int start,int end)
{
if(end