DSA problem
Maximum Sum Circular Subarray
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: 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.
Examples
Example 1
Input:
nums = [1,-2,3,-2]Output:
3Explanation: Subarray [3] has maximum sum 3.
Example 2
Input:
nums = [5,-3,5]Output:
10Explanation: Subarray [5,5] has maximum sum 5 + 5 = 10, wrapping around the end of the array.
Example 3
Input:
nums = [-3,-2,-3]Output:
-2Explanation: Subarray [-2] has maximum sum -2; the array is all negative so the answer is the largest single element.
Constraints
- n == nums.length
- 1 <= n <= 3 * 10^4
- -3 * 10^4 <= nums[i] <= 3 * 10^4
3 hints and a full solution walkthrough with step-by-step visualizations are available in the practice editor.