# pylint: disable-all
import unittest

"""
Description:
    Given an integer array nums, find the contiguous subarray (containing at least one number) which has the largest sum and return its sum.

Example:
Input: [-2,1,-3,4,-1,2,1,-5,4],
Output: 6
Explanation: [4,-1,2,1] has the largest sum = 6.

Follow up:
    If you have figured out the O(n) solution, try coding another solution using the divide and conquer approach, which is more subtle.
"""
nums1 = [-2, 1, -3, 4, -1, 2, 1, -5, 4]
nums2 = []


class Solution:
    def maxSubArray(self, nums) -> int:
        if not nums:
            return 0
        for i in range(1, len(nums)):
            if nums[i - 1] > 0:
                nums[i] += nums[i - 1]

        return max(nums)

class MyTest(unittest.TestCase):
    def test_example1(self):
        solution = Solution()
        self.assertEqual(solution.maxSubArray(nums1), 6)

    def test_example2(self):
        solution = Solution()
        self.assertEqual(solution.maxSubArray(nums2), 0)
    

if __name__ == '__main__':
    unittest.main()
