Maximum Subarray

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

A subarray is a contiguous part of an array.

Example 1:

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

Example 2:

Input: nums = [1]
Output: 1

Example 3:

Input: nums = [5,4,-1,7,8]
Output: 23

Constraints:

• 1 <= nums.length <= 105
• -104 <= nums[i] <= 104

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.

SOLUTION:

class Solution:
    def maxSubArray(self, nums: List[int]) -> int:
        n = len(nums)
        maxSoFar = float('-inf')
        maxEndingHere = 0
        for i in range(n):
            maxEndingHere += nums[i]
            maxSoFar = max(maxSoFar, maxEndingHere)
            maxEndingHere = max(maxEndingHere, 0)
        return maxSoFar