Maximize the Sum of a Nonempty Circular Array Segment

### Problem Treat the end of `nums` as adjacent to its beginning. Return the largest sum of a nonempty contiguous circular segment, using each array position at most once. A segment may wrap across the end but cannot make a second lap. ```cpp class Solution { public: int maxSubarraySumCircular(vector<int>& nums); }; ``` ### Examples **Example 1:** ```text Input: nums = [8,-4,7] Output: 15 Explanation: The wrapping segment[7,8] skips-4 and has sum15. ``` **Example 2:** ```text Input: nums = [-5,-1,-2] Output: -1 Explanation: A nonempty segment is required; the singleton-1 is best. ``` ### Constraints - `n == nums.length`; `1 <= n <= 3*10^4`. - `-3*10^4 <= nums[i] <= 3*10^4`. ### Contract considerations The returned answer is a sum, and a length-n segment is allowed exactly once around the buffer. ```hint Read the boundary condition What contiguous interval would be omitted by a wrapping segment? ``` ### Boundary reminders The returned answer is a sum, and a length-n segment is allowed exactly once around the buffer.