<p>Given an integer array <code>nums</code> where the elements are sorted in <strong>ascending order</strong>, convert <em>it to a </em><span data-keyword="height-balanced"><strong><em>height-balanced</em></strong></span> <em>binary search tree</em>.</p> <p> </p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://assets.leetcode.com/uploads/2021/02/18/btree1.jpg" style="width: 302px; height: 222px;" /> <pre> <strong>Input:</strong> nums = [-10,-3,0,5,9] <strong>Output:</strong> [0,-3,9,-10,null,5] <strong>Explanation:</strong> [0,-10,5,null,-3,null,9] is also accepted: <img alt="" src="https://assets.leetcode.com/uploads/2021/02/18/btree2.jpg" style="width: 302px; height: 222px;" /> </pre> <p><strong class="example">Example 2:</strong></p> <img alt="" src="https://assets.leetcode.com/uploads/2021/02/18/btree.jpg" style="width: 342px; height: 142px;" /> <pre> <strong>Input:</strong> nums = [1,3] <strong>Output:</strong> [3,1] <strong>Explanation:</strong> [1,null,3] and [3,1] are both height-balanced BSTs. </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 <= nums.length <= 10<sup>4</sup></code></li> <li><code>-10<sup>4</sup> <= nums[i] <= 10<sup>4</sup></code></li> <li><code>nums</code> is sorted in a <strong>strictly increasing</strong> order.</li> </ul>