108. Convert Sorted Array to Binary Search Tree

https://leetcode.com/problems/convert-sorted-array-to-binary-search-tree/

https://leetcode.com/problems/convert-sorted-array-to-binary-search-tree/discuss/35220/My-Accepted-Java-Solution

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
class Solution {
    public TreeNode sortedArrayToBST(int[] nums) {
        if(nums==null) return null;
        return treeBuilder(0,nums.length-1,nums);
    }
    public TreeNode treeBuilder(int start,int end, int[] nums){
        if(start>end) return null;
        int mid=start+(end-start)/2;
        TreeNode node=new TreeNode(nums[mid]);
        node.left=treeBuilder(start,mid-1,nums);
        node.right=treeBuilder(mid+1,end,nums);
        return node;
    }
}