An integer array is called arithmetic if it consists of at least three elements and if the difference between any two consecutive elements is the same.
For example, [1,3,5,7,9], [7,7,7,7], and [3,-1,-5,-9] are arithmetic sequences.
Given an integer array nums, return the number of arithmetic subarrays of nums.
A subarray is a contiguous subsequence of the array.
1 <= nums.length <= 5000-1000 <= nums[i] <= 1000nums = [1,2,3,4]3nums = [1]0