LeetCode - 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.

Example:

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

algorithm that operates on arrays: it starts at the left end (element A[1]) and scans through to the right end (element A[n]), keeping track of the maximum sum subvector seen so far. The maximum is initially A[0]. Suppose we've solved the problem for A[1 .. i - 1]; how can we extend that to A[1 .. i]? The maximum
sum in the first I elements is either the maximum sum in the first i - 1 elements (which we'll call MaxSoFar), or it is that of a subvector that ends in position i (which we'll call MaxEndingHere).

 

MaxEndingHere is either A[i] plus the previous MaxEndingHere, or just A[i], whichever is larger.

class Solution {
    public int maxSubArray(int[] nums) {
        if(nums == null || nums.length == 0){
            return 0;
        }
        int maxSoFar = nums[0];
        int maxEndingHere = nums[0];
        for(int i = 1; i < nums.length; i++){
            maxEndingHere = Math.max(maxEndingHere + nums[i], nums[i]);
            maxSoFar = Math.max(maxSoFar, maxEndingHere);
        }
        return maxSoFar;
    }
    

}