Given an array arr and an integer k, partition it into contiguous subarrays of length at most k. After partitioning, every value in a subarray becomes that subarray's maximum. Return the largest possible sum of the resulting array. The input is JSON {arr, k}.
Input: JSON {arr, k}.
Output: Integer — the maximum sum after partitioning.
Input: {"arr":[1,15,7,9,2,5,10],"k":3}
Output: 84
Explanation: Partition to maximize each block's max.Input: {"arr":[1],"k":1}
Output: 1
Explanation: Single element.Input: {"arr":[1,4,1,5,7,3,6,1,9,9,3],"k":4}
Output: 83
Explanation: Optimal partitioning.1<=n<=5001<=k<=n