Maximum subarray problem: 2D Kadane's algorithm

/**
* Get max sum from 2D array example
* Use Kadane's algorithm
* Maximum subarray problem: https://en.wikipedia.org/wiki/Maximum_subarray_problem
* Author: https://github.com/InterVi
*/
import java.lang.Math;
import java.util.AbstractMap.SimpleEntry;
import java.util.Map.Entry;

public class MaxSumExample {
  public static void main(String[] args) { //testing
    int[][] test = {
      {-1, -2, -1},
      {-20},
      {-40, -50},
      {-1, 2, 3, -4, 5}, //6
      {4, -1, 2, 1}, //6, least summands, this will print
      {1, 1},
      {2, -4, -1},
      {1, 1}
    };
    System.out.print(maxSum2D(test, false));
  }

  /**
  * @return key - summands, value - result
  */
  public static Entry<Integer, Integer> maxSum(int[] a) {
    int result = a[0]; //get first value for correct comparison
    int sum = a[0];
    int items = 1; //summands
    for (int i = 1; i < a.length; i++) {
      sum = Math.max(sum + a[i], a[i]); //first step getting max sum, temporary value
      //result = Math.max(result, sum); //if no need summands
      if (sum > result) { //save current max sum
        result = sum;
        items++; //update summands
      }
    }
    return new SimpleEntry<>(items, result);
  }

  /**
  * @param array
  * @param useLength true - use length least value, false - use summands least value for get index
  * @return key - index in array with max sum, value - sum
  */
  public static Entry<Integer, Integer> maxSum2D(int array[][], boolean useLength){
    int lastIndex = 0; //index with max sum
    int lastMax = Integer.MIN_VALUE; //max sum
    int lastLength = 0; //last array[i].length or summands, for get index with the least value (length or summands)
    for (int i = 0; i < array.length; i++) {
      Entry<Integer, Integer> entry = maxSum(array[i]); //get sum and summands in subarray
      int newLength = useLength ? array[i].length : entry.getKey(); //use length or summands
      if (entry.getValue() == lastMax && newLength <= lastLength) { //save index with the least value (length or summands)
        lastIndex = i;
      } else if (entry.getValue() > lastMax) { //update index and max sum value
        lastIndex = i;
        lastMax = entry.getValue();
      }
      lastLength = newLength; //save length or summands for use next iteration
    }
    return new SimpleEntry<>(lastIndex, lastMax);
  }
}