#823 · #2551 · Put Marbles in Bags(将珠子放入背包中)

You are given an array weights and an integer k. Split the array into k contiguous groups; the score of a group is the sum of its first and last weight, and the total score is the sum over groups. Return the difference between the maximum and minimum possible total score. Constraints: 2 <= k <= weights.length <= 10^5, 1 <= weights[i] <= 10^9.