2763. Sum of Imbalance Numbers of All Subarrays

The imbalance number of a 0-indexed integer array arr of length n is defined as the number of indices in sarr = sorted(arr) such that: - 0 <= i < n - 1, and - sarr[i+1] - sarr[i] > 1 Here, sorted(arr) is the function that returns the sorted version of arr. Given a 0-indexed integer array nums, return the sum of imbalance numbers of all its subarrays. A subarray is a contiguous non-empty seque