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

#include <stdio.h>
#include <limits.h>

int maxSubArray(int* nums, int numsSize) {
    int maxi = INT_MIN;
    int sum = 0;
    for (int i = 0; i < numsSize; i++) {
        sum += nums[i];
        maxi = (sum > maxi) ? sum : maxi;
        
        if (sum < 0) {
            sum = 0;
        }
    }
    return maxi;
}