LeetCode-in-All

53. Maximum Subarray

Medium

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:

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

func maxSubArray(nums []int) int {
	sum, max := nums[0], nums[0]
	for i := 1; i < len(nums); i++ {
		if sum < 0 {
			sum = 0
		}
		sum += nums[i]
		if sum > max {
			max = sum
		}
	}
	return max
}