Question

I have the following implementation of Kadane’s algorithm in java. It is basically to find the maximum sum of contiguous subarray.

String[] numbers = string.split(",");
                int max_so_far = 0;
                int max_ending_here = 0;
                for (int i = 0; i < numbers.length-1;i++){
                     max_ending_here = max_ending_here + Integer.parseInt(numbers[i]);
                     if (max_ending_here < 0)
                         max_ending_here = 0;
                     if (max_so_far < max_ending_here)
                          max_so_far = max_ending_here;
                }
                System.out.println(max_so_far);

However this doesn’t work if there is a combination of a negative and positive number in an array, for example the following:

2,3,-2,-1,10

Which should return a 12 as a maximum. As of now it returns 5

Answer 1

You algorithm implementation looks ok, but your loop conditional i < numbers.length-1 does not: it stops just 1 short of the end of the array. i < numbers.length should do it 🙂