Why does the following algorithm print random string of characters instead of an array?

Question

Here is my homework:

Write a program which does the following: It returns an integer array arr2 of length n whose first k elements are the same as the first k elements of arr, and whose remaining elements consist of repeating blocks of the first k elements. You can assume array arr has at least k elements. The function should return null if either k or n is not positive.

Examples:

       fill({1,2,3,5, 9, 12,2,
        1},
        3, 10) returns {1,2,3,1,2,3,1,2,3,1}.
        fill({4, 2, 3,
        12}, 1, 5) returns {4, 4, 4, 4, 4}.
        fill({2, 6, 9, 0, 3},
        0, 4) returns null.

Here is my code:

public static void main (String[] args){
    int [] result = fill(new int[]{1, 2, 3, 5, 9, 12, 2, 1}, 3, 10);
    System.out.println(result);
}

    public static int[] fill(int[] arr, int k, int n){
        int[] arr2 = new int[n];
        int cnt = 0;
        if (k > 0 && n > 0)
        {
            while (cnt != n)
            {

                for (int j = 0; j < k; j++)
                {
                    if (cnt != n)
                    {
                        arr2[cnt] = arr[j];
                        cnt++;
                    }
                    else
                        break;
                }
            }
        }
        else
            return null;

        return arr2;
    }