"""
53. Maximum Subarray
Difficulty: Medium
https://leetcode.com/problems/maximum-subarray/

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Given an integer array nums, find the subarray with the largest sum,
and return its sum.



Example 1:

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

Example 2:

Input: nums = [1]
Output: 1
Explanation: The subarray [1] has the largest sum 1.

Example 3:

Input: nums = [5,4,-1,7,8]
Output: 23
Explanation: The subarray [5,4,-1,7,8] has the largest sum 23.



Constraints:

        • 1 <= nums.length <= 10^5

        • -10^4 <= nums[i] <= 10^4



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.
"""


class Solution:
    def maxSubArray(self, nums: list[int]) -> int:
        best, total = nums[0], nums[0]

        for i in range(1, len(nums)):
            if total < 0:
                total = nums[i]
            else:
                total = total + nums[i]
            best = max(best, total)

        return best