<p>Given an integer array <code>nums</code> and an integer <code>k</code>, return <em>the length of the shortest non-empty <strong>subarray</strong> of </em><code>nums</code><em> with a sum of at least </em><code>k</code>. If there is no such <strong>subarray</strong>, return <code>-1</code>.</p> <p>A <strong>subarray</strong> is a <strong>contiguous</strong> part of an array.</p> <p> </p> <p><strong>Example 1:</strong></p> <pre><strong>Input:</strong> nums = [1], k = 1 <strong>Output:</strong> 1 </pre><p><strong>Example 2:</strong></p> <pre><strong>Input:</strong> nums = [1,2], k = 4 <strong>Output:</strong> -1 </pre><p><strong>Example 3:</strong></p> <pre><strong>Input:</strong> nums = [2,-1,2], k = 3 <strong>Output:</strong> 3 </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 <= nums.length <= 10<sup>5</sup></code></li> <li><code>-10<sup>5</sup> <= nums[i] <= 10<sup>5</sup></code></li> <li><code>1 <= k <= 10<sup>9</sup></code></li> </ul>