Maximum Subarray Sum in Java: Explanation & Practice

Problem summary

Write a program that finds the maximum sum of any contiguous subarray (Kadane's algorithm).

Starter code

public class Main {
    public static void main(String[] args) {
        int[] arr = {-2, 1, -3, 4, -1, 2, 1, -5, 4}; // Test case 1
        
        // Find max subarray sum
        // Print: Max sum: <result>
    }
}

Expected output and test cases

• [4,-1,2,1] = 6

  Max sum: 6

• All positive sums

  Max sum: 5

• All negative, pick largest

  Max sum: -1

Hints

1. Kadane's: track current sum and max sum
2. Reset current sum if it goes negative
3. Update max whenever current exceeds it

Related Arrays exercises

• Practice Binary Search in Java
• Practice Find Pair with Sum in Java
• Practice Leaders in Array in Java

Practice all Arrays exercises · Run this idea in the Java compiler