class Solution {
  public int maxSubArray(int[] nums) {
      int maxSum = Integer.MIN_VALUE, sum = 0;
      for(int index = 0; index < nums.length; index++) {
          sum += nums[index];
          
          if(sum > maxSum) {
              maxSum = sum;
          } 
          
          if(sum < 0) {
              sum = 0;
          }
      }
      
      return maxSum;
  }
}

The above solution is for the "Maximum Subarray" problem. It efficiently finds the contiguous subarray with the largest sum within a given array nums. Here's how the code works:

1. The maxSubArray function takes an integer array nums as input and returns an integer representing the maximum sum of a contiguous subarray.
2. It initializes maxSum to the minimum possible value (Integer.MIN_VALUE) and sum to 0.
3. The loop iterates through the array using the index variable.
4. Inside the loop:
   • The current element is added to the sum.
   • If the sum becomes greater than the current maxSum, the maxSum is updated.
   • If the sum becomes negative, it means that continuing the current subarray won't lead to a larger sum, so the sum is reset to 0 to start a new potential subarray.
5. Finally, the function returns maxSum, which holds the maximum sum of a contiguous subarray.

The solution follows the Kadane's algorithm, which is an efficient algorithm for finding the maximum subarray sum in an array. It keeps track of the current sum and resets it when a negative sum is encountered, while also maintaining the overall maximum sum encountered so far.

This code provides an optimal solution for finding the maximum subarray sum and is suitable for larger arrays as well.