1814. Count Nice Pairs in an Array

You are given an array nums that consists of non-negative integers. Let us define rev(x) as the reverse of the non-negative integer x. For example, rev(123) = 321, and rev(120) = 21. A pair of indices (i, j) is nice if it satisfies all of the following conditions: - 0 <= i < j < nums.length - nums[i] + rev(nums[j]) == nums[j] + rev(nums[i]) Return the number of nice pairs of indices. Since that