# Maximum Sum Circular Subarray

Moderate
0/80
Average time to solve is 10m

## Problem statement

You have been given a circular array/list ‘ARR’ containing ‘N’ integers. You have to find out the maximum possible sum of a non-empty subarray of ‘ARR’.

A circular array is an array/list in which the end of the array connects to the beginning of the array.

A subarray may only include each element of the fixed buffer of ‘ARR’ at most once. (Formally, for a subarray ‘ARR[i]’, ‘ARR[i+1]’, ..., ‘ARR[j]’, there does not exist ‘i’ <= ‘k1’, ‘k2’ <= ‘j’ with ‘k1’ % ‘N’ = k2 % ‘N’.)

For Example:

``````The ‘ARR’ = [1, 2, -3, -4, 5], the subarray [5, 1, 2] has the maximum possible sum which is 8. This is possible as 5 is connected to 1 because ‘ARR’ is a circular array.
``````
Detailed explanation ( Input/output format, Notes, Images )
Constraints:
``````1 <= T <= 100
1 <= N <= 10^5
-10^5 <= ARR[i] <= 10^5

Time Limit: 1 sec
``````
##### Sample Input 1:
``````2
3
-2 -3 -1
4
1 2 3 4
``````
##### Sample Output 1:
``````-1
10
``````
##### Explanation Of Sample Input 1:
``````For the first test case:
The sub-array [-1] in the given ‘ARR’ has the maximum sum which is -1.

For the second test case:
The sub-array [1, 2, 3, 4] in the given ‘ARR’ has the maximum sum which is 10.
``````
##### Sample Input 2:
``````2
4
3 1 -2 9
1
10
``````
##### Sample Output 2:
``````13
10
``````
##### Explanation Of Sample Input 2:
``````For the first test case:
The sub-array [9, 3, 1]  in the given ‘ARR’ has the maximum sum which is 13. Since ‘ARR’ is a circular array/list,  9 is connected to 3.

For the second test case:
The sub-array [10] in the given  ‘ARR’ has the maximum sum which is 10.
``````
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