CheckDuplicates.java

public class CheckDuplicates {
    public void hasDuplicates(int[] arrA) {

        for (int i = 0; i < arrA.length; i++) {
            //check if element is negative, if yes the we have found the duplicate
            if (arrA[Math.abs(arrA[i])] < 0) {
                System.out.println("Array has duplicates : " + Math.abs(arrA[i]));
            } else {
                arrA[Math.abs(arrA[i])] = arrA[Math.abs(arrA[i])] * -1;
            }
        }
    }

    public static void main(String[] args) {
        int a[] = {1, 6, 5, 2, 3, 3, 2};
        new CheckDuplicates().hasDuplicates(a);
    }
}

how to handle 0