Given an integer array nums, find the contiguous subarray (containing at least one number) which has the largest sum and return its sum. https://leetcode.com/explore/challenge/card/30-day-leetcoding-challenge/528/week-1/3285/

MaxSubArray.java

public class MaxSubArray {

  public static void main(String[] args) {
  MaxSubArray problem = new MaxSubArray();

    int result1 = problem.calculate(new int[] { -2,1,-3,4,-1,2,1,-5,4 });
    System.out.println("Expected: 6, Result: " + result1);
  }

  public int calculate(int[] nums) {
    
    int subSum = nums[0];
    int maxSum = subSum;
    
    for(int i=1; i<nums.length; i++){
      
      // reset sub-sum if current num is greater than pre-sum
      if(nums[i] > subSum+nums[i]) {
        subSum = 0;
      }
      
      maxSum = Math.max(maxSum,subSum+nums[i]);
      
      subSum += nums[i];
      
    }
    return maxSum;
  }
}

very complex question