Maximum Sum Circular Subarray
You are given a circular integer array nums of length n, return the maximum possible sum of a non-empty subarray of nums.
A circular array means the end of the array connects to the beginning of the array. Formally, the next element of nums[i] is nums[(i + 1) % n] and the previous element of nums[i] is nums[(i - 1 + n) % n].
A subarray may only include each element of the fixed buffer nums at most once. Formally, for a subarray nums[i], nums[i + 1], ..., nums[j], there does not exist i <= k1, k2 <= j with k1 % n == k2 % n.
Example 1:
Input: nums = [-2,4,-5,4,-5,9,4]
Output: 15Explanation: Subarray [-2,4,9,4] has maximum sum 15.
Example 2:
Input: nums = [2,3,-4]
Output: 5Constraints:
n == nums.length1 <= n <= 3 * 10,000-30,000 <= nums[i] <= 30,000