Leetcode 1574. Shortest Subarray to be Removed to Make Array Sorted

Given an array, remove the shortest contiguous subarray (possibly empty) so that the remaining elements — the concatenation of a prefix and a suffix — are non-decreasing. The core approach is to exploit the maximal non-decreasing prefix and suffix and merge them (via two-pointer/binary-search) to minimize the removed length; n ≤ 10^5.