Leetcode 3500. Minimum Cost to Divide Array Into Subarrays

Partition nums into contiguous subarrays to minimize the total sum where each segment [l..r] contributes (prefix_sum_up_to_r + k * segment_index) * (sum of cost[l..r]). Algorithmically this is a DP over partition points with costs expressed via prefix sums, often optimized using line container/convex-hull techniques or other DP speedups.