You are given an integer array nums and a positive integer k. Return the sum of the maximum and minimum elements of all subarrays with at most k elements.

 

Example 1:

Input: nums = [1,2,3], k = 2

Output: 20

Explanation:

The subarrays of nums with at most 2 elements are:

Subarray Minimum Maximum Sum
[1] 1 1 2
[2] 2 2 4
[3] 3 3 6
[1, 2] 1 2 3
[2, 3] 2 3 5
Final Total     20

The output would be 20.

Example 2:

Input: nums = [1,-3,1], k = 2

Output: -6

Explanation:

The subarrays of nums with at most 2 elements are:

Subarray Minimum Maximum Sum
[1] 1 1 2
[-3] -3 -3 -6
[1] 1 1 2
[1, -3] -3 1 -2
[-3, 1] -3 1 -2
Final Total     -6

The output would be -6.

 

Constraints: