108. Convert Sorted Array to Binary Search Tree

题目链接：convert-sorted-array-to-binary-search-tree

/** * Given an array where elements are sorted in ascending order, convert it to a height balanced BST. * */public class ConvertSortedArrayToBinarySearchTree {public class TreeNode {int val;TreeNode left;TreeNode right;TreeNode(int x) {val = x;}}//32 / 32 test cases passed.//Status: Accepted//Runtime: 272 ms//Submitted: 0 minutes ago    public TreeNode sortedArrayToBST(int[] num) {    return sortedArrayToBST(num, 0, num.length - 1);    }    public TreeNode sortedArrayToBST(int[] num, int left, int right) {        if(left > right) return null;    int mid = (left + right) / 2;    TreeNode root = new TreeNode(num[mid]);    root.left = sortedArrayToBST(num, left, mid - 1);    root.right = sortedArrayToBST(num, mid + 1, right);    return root;    }public static void main(String[] args) {// TODO Auto-generated method stub}}