Arithmetic Slices
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
3We have 3 arithmetic slices in nums: [1, 2, 3], [2, 3, 4] and [1,2,3,4] itself.
Example 2
Input
nums = [1]Output
0The array has fewer than three elements, so it has no arithmetic subarrays.
Constraints
- 1 <= nums.length <= 5000
- -1000 <= nums[i] <= 1000