<p>You are given a <strong>0-indexed </strong>integer array <code>nums</code>.</p> <p>The <strong>distinct count</strong> of a subarray of <code>nums</code> is defined as:</p> <ul> <li>Let <code>nums[i..j]</code> be a subarray of <code>nums</code> consisting of all the indices from <code>i</code> to <code>j</code> such that <code>0 <= i <= j < nums.length</code>. Then the number of distinct values in <code>nums[i..j]</code> is called the distinct count of <code>nums[i..j]</code>.</li> </ul> <p>Return <em>the sum of the <strong>squares</strong> of <strong>distinct counts</strong> of all subarrays of </em><code>nums</code>.</p> <p>Since the answer may be very large, return it <strong>modulo</strong> <code>10<sup>9</sup> + 7</code>.</p> <p>A subarray is a contiguous <strong>non-empty</strong> sequence of elements within an array.</p> <p> </p> <p><strong>Example 1:</strong></p> <pre> <strong>Input:</strong> nums = [1,2,1] <strong>Output:</strong> 15 <strong>Explanation:</strong> Six possible subarrays are: [1]: 1 distinct value [2]: 1 distinct value [1]: 1 distinct value [1,2]: 2 distinct values [2,1]: 2 distinct values [1,2,1]: 2 distinct values The sum of the squares of the distinct counts in all subarrays is equal to 1<sup>2</sup> + 1<sup>2</sup> + 1<sup>2</sup> + 2<sup>2</sup> + 2<sup>2</sup> + 2<sup>2</sup> = 15. </pre> <p><strong>Example 2:</strong></p> <pre> <strong>Input:</strong> nums = [2,2] <strong>Output:</strong> 3 <strong>Explanation:</strong> Three possible subarrays are: [2]: 1 distinct value [2]: 1 distinct value [2,2]: 1 distinct value The sum of the squares of the distinct counts in all subarrays is equal to 1<sup>2</sup> + 1<sup>2</sup> + 1<sup>2</sup> = 3.</pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 <= nums.length <= 10<sup>5</sup></code></li> <li><code>1 <= nums[i] <= 10<sup>5</sup></code></li> </ul>