Leetcode 3196. Maximize Total Cost of Alternating Subarrays

Partition the array into contiguous subarrays to maximize the sum of each segment's alternating-signed sum (cost(l,r) = nums[l] - nums[l+1] + ...). The challenge is deciding partition boundaries (i.e., which elements get plus or minus signs within segments) to maximize the total, with n up to 1e5.