leetcode 523 : handling zeros correctly

LeetCodeSolution523.java

import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;

/**
 * Default solution you find in youtube won't work for [4, 1, 0] , k = 3. So, we need to add extra check for
 * this corner case.
 * Test cases 4, 5 and 6 pose interesting scenario because of 0s.
 */
public class Solution {
    /**
     * Placeholder for the actual test method.
     *
     * @param nums input array
     * @param k    integer k
     * @return true if a continuous subarray sum is a multiple of k, false otherwise
     */
    public boolean checkSubarraySum(int[] nums, int k) {
        Map<Integer, Integer> indexMap = new HashMap<>();
        int sum = 0;
        boolean prevZero = false; // to handle corner case scenario with zeros
        for (int index = 0; index < nums.length; ++index) {
            sum = (sum + nums[index]);
            if (indexMap.containsKey(sum % k)) {
                if (nums[index] == 0 && !prevZero) {
                    prevZero = (nums[index] == 0) ? true : false;
                    continue;
                }
                return true;
            } else {
                indexMap.put(sum % k, index);
            }
            prevZero = (nums[index] == 0) ? true : false;
        }
        return false;
    }

    public static void main(String[] args) {
        Solution solution = new Solution();

        int[][] testInputs = {
                { 23, 2, 4, 6, 7 }, // Example 1
                { 23, 2, 6, 4, 7 }, // Example 2
                { 23, 2, 6, 4, 7 }, // Example 3
                { 1, 0 }, // Example 4
                { 0, 0 }, // Example 5
                { 5, 0, 0, 0 }, // Additional test case
                { 1, 2, 3 }, // Additional test case
                { 1, 2, 3, 4, 5 }, // Additional test case
                { 0, 1, 0, 3, 0, 4, 0, 4, 0 } // Additional test case
        };
        int[] kValues = { 6, 6, 13, 2, 1, 3, 5, 9, 5 };
        boolean[] expectedResults = { true, true, false, false, true, true, true, true, false };

        for (int i = 0; i < testInputs.length; i++) {
            try {
                boolean result = solution.checkSubarraySum(testInputs[i], kValues[i]);
                System.out.printf("Test case %d:%n", i + 1);
                System.out.printf("Input: nums = %s, k = %d%n", Arrays.toString(testInputs[i]), kValues[i]);
                System.out.printf("Expected: %b%n", expectedResults[i]);
                System.out.printf("Got: %b%n", result);
                System.out.printf("Test %s%n%n", result == expectedResults[i] ? "PASSED" : "FAILED");
            } catch (UnsupportedOperationException e) {
                System.out.printf("Test case %d: Not implemented\n", i + 1);
            }
        }
    }
}