public class Solution
extends Object
413 - Arithmetic Slices\.
Medium
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.
**Example 1:**
**Input:** nums = [1,2,3,4]
**Output:** 3
**Explanation:** We have 3 arithmetic slices in nums: [1, 2, 3], [2, 3, 4] and [1,2,3,4] itself.
**Example 2:**
**Input:** nums = [1]
**Output:** 0
**Constraints:**
* `1 <= nums.length <= 5000`
* `-1000 <= nums[i] <= 1000`