Skip to content

53. Maximum Subarray

Difficulty Topics

Description

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

maximum-subarray.py
class Solution:
    def maxSubArray(self, nums: List[int]) -> int:
        res = curr = nums[0]

        for x in nums[1:]:
            curr = max(curr + x, x)
            res = max(res, curr)

        return res