human
Solve in Python:
Given a circular array C of integers represented by A, find the maximum possible sum of a non-empty subarray of C.
Here, a circular array means the end of the array connects to the beginning of the array.  (Formally, C[i] = A[i] when 0 <= i < A.length, and C[i+A.length] = C[i] when i >= 0.)
Also, a subarray may only include each element of the fixed buffer A at most once.  (Formally, for a subarray C[i], C[i+1], ..., C[j], there does not exist i <= k1, k2 <= j with k1 % A.length = k2 % A.length.)
 

Example 1:
Input: [1,-2,3,-2]
Output: 3
Explanation: Subarray [3] has maximum sum 3

Example 2:
Input: [5,-3,5]
Output: 10
Explanation: Subarray [5,5] has maximum sum 5 + 5 = 10

Example 3:
Input: [3,-1,2,-1]
Output: 4
Explanation: Subarray [2,-1,3] has maximum sum 2 + (-1) + 3 = 4

Example 4:
Input: [3,-2,2,-3]
Output: 3
Explanation: Subarray [3] and [3,-2,2] both have maximum sum 3

Example 5:
Input: [-2,-3,-1]
Output: -1
Explanation: Subarray [-1] has maximum sum -1

 
Note: 

-30000 <= A[i] <= 30000
1 <= A.length <= 30000

Give me a Python program to find the maximum possible sum of a non-empty subarray of C?
assistant
#Here is Python program to find the maximum possible sum of a non-empty subarray of C.

class Solution:
    def maxSubarraySumCircular(self, A: List[int]) -> int:
        max1 = -float('inf')
        maxc = -float('inf')
        for i in range(len(A)):
            maxc = max(maxc+A[i],A[i])
            max1 = max(max1,maxc)
        
        
        min1 = float('inf')
        minc = float('inf')
        for i in range(len(A)):
            minc = min(minc+A[i],A[i])
            min1 = min(min1,minc)
        
        if min1==sum(A):
            return max1

        return max(max1,sum(A)-min1)