Example: Maximum Product Subarray - Brute Force in Java

// Maximum Product Subarray - Brute Force
import java.util.Scanner; // Included as per template, though not strictly used in this example.

// Main class containing the entry point of the program
public class Main {
    public static void main(String[] args) {
        int[] nums = {2, 3, -2, 4};
        // int[] nums = {-2, 0, -1}; // Another test case: expected 0
        // int[] nums = {-2, -3, -1}; // Another test case: expected 6 (from [-2, -3])

        if (nums == null || nums.length == 0) {
            System.out.println("The array is empty. Max product: 0");
            return;
        }

        // Step 1: Initialize max_product with the first element of the array
        // This handles cases where all elements are negative or single element arrays.
        long max_product = nums[0]; 

        // Step 2: Iterate through all possible starting points (i)
        for (int i = 0; i < nums.length; i++) {
            long current_product = 1; // Initialize product for current subarray

            // Step 3: Iterate through all possible ending points (j) from the current start
            for (int j = i; j < nums.length; j++) {
                // Step 4: Multiply current_product by the element at index j
                current_product *= nums[j];

                // Step 5: Update max_product if current_product is greater
                if (current_product > max_product) {
                    max_product = current_product;
                }
            }
        }
        
        System.out.println("Maximum product subarray (Brute Force): " + max_product);
    }
}