3689. Maximum Total Subarray Value I

You are given an integer array nums of length n and an integer k.

You need to choose exactly k non-empty subarrays nums[l..r] of nums. Subarrays may overlap, and the exact same subarray (same l and r) can be chosen more than once.

The value of a subarray nums[l..r] is defined as: max(nums[l..r]) - min(nums[l..r]).

The total value is the sum of the values of all chosen subarrays.

Return the maximum possible total value you can achieve.

class Solution {
public:
    long long maxTotalValue(vector<int>& nums, long long k) {
        return k * (*max_element(begin(nums), end(nums)) - *min_element(begin(nums), end(nums)));
    }
};