Maximum Sum Circular Subarray

0Medium

Maximum Sum Circular Subarray

Given a circular integer array nums, return the maximum possible sum of a non-empty subarray of nums. A circular subarray can wrap around.

Example 1:

Input: nums = [1,-2,3,-2] Output: 3

Example 2:

Input: nums = [5,-3,5] Output: 10

Example 3:

Input: nums = [-3,-2,-3] Output: -2

Jnaneshwara Reddy Satti

Builder · ClearCode

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Algorithm Visualizer

O(N)

Before starting this video, please check the description to ensure you know the prerequisites. If you're comfortable with arrays and hash maps, let's go!

TEST CASE: []O(1)

clearcode.in

Execution Trace

1def max_subarray_sum_circular(nums):

2 def kadane(arr):

3 max_ending_here = max_so_far = arr[0]

4 for x in arr[1:]:

5 max_ending_here = max(x, max_ending_here + x)

6 max_so_far = max(max_so_far, max_ending_here)

7 return max_so_far

9 max_kadane = kadane(nums)

10 max_wrap = sum(nums) + kadane([-x for x in nums])

11 return max(max_kadane, max_wrap) if max_kadane > 0 else max_kadane

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