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

/**
 * @param {number[]} nums
 * @return {number}
 */
var maxSubArray = function(nums) {
    let maxi = Number.MIN_SAFE_INTEGER
    let sum = 0

    for (const num of nums) {
        sum += num
        maxi = Math.max(sum, maxi)
        if (sum < 0) {
            sum = 0
        }
    }

    return maxi
};

export { maxSubArray }